Add install_mirrors to EnvironmentOptions (#15937)

## Summary

Add install_mirrors to EnvironmentOptions
Relates #14720

## Test Plan

Tests with existing tests

docs/reference/cli.md

@@ -3405,7 +3405,7 @@ uv python list [OPTIONS] [REQUEST]
 <p>This setting has no effect when used in the <code>uv pip</code> interface.</p>
 <p>May also be set with the <code>UV_PROJECT</code> environment variable.</p></dd><dt id="uv-python-list--python-downloads-json-url"><a href="#uv-python-list--python-downloads-json-url"><code>--python-downloads-json-url</code></a> <i>python-downloads-json-url</i></dt><dd><p>URL pointing to JSON of custom Python installations.</p>
 <p>Note that currently, only local paths are supported.</p>
-<p>May also be set with the <code>UV_PYTHON_DOWNLOADS_JSON_URL</code> environment variable.</p></dd><dt id="uv-python-list--quiet"><a href="#uv-python-list--quiet"><code>--quiet</code></a>, <code>-q</code></dt><dd><p>Use quiet output.</p>
+</dd><dt id="uv-python-list--quiet"><a href="#uv-python-list--quiet"><code>--quiet</code></a>, <code>-q</code></dt><dd><p>Use quiet output.</p>
 <p>Repeating this option, e.g., <code>-qq</code>, will enable a silent mode in which uv will write no output to stdout.</p>
 </dd><dt id="uv-python-list--show-urls"><a href="#uv-python-list--show-urls"><code>--show-urls</code></a></dt><dd><p>Show the URLs of available Python downloads.</p>
 <p>By default, these display as <code>&lt;download available&gt;</code>.</p>
@@ -3477,7 +3477,7 @@ uv python install [OPTIONS] [TARGETS]...
 <p>May also be set with the <code>UV_MANAGED_PYTHON</code> environment variable.</p></dd><dt id="uv-python-install--mirror"><a href="#uv-python-install--mirror"><code>--mirror</code></a> <i>mirror</i></dt><dd><p>Set the URL to use as the source for downloading Python installations.</p>
 <p>The provided URL will replace <code>https://github.com/astral-sh/python-build-standalone/releases/download</code> in, e.g., <code>https://github.com/astral-sh/python-build-standalone/releases/download/20240713/cpython-3.12.4%2B20240713-aarch64-apple-darwin-install_only.tar.gz</code>.</p>
 <p>Distributions can be read from a local directory by using the <code>file://</code> URL scheme.</p>
-<p>May also be set with the <code>UV_PYTHON_INSTALL_MIRROR</code> environment variable.</p></dd><dt id="uv-python-install--native-tls"><a href="#uv-python-install--native-tls"><code>--native-tls</code></a></dt><dd><p>Whether to load TLS certificates from the platform's native certificate store.</p>
+</dd><dt id="uv-python-install--native-tls"><a href="#uv-python-install--native-tls"><code>--native-tls</code></a></dt><dd><p>Whether to load TLS certificates from the platform's native certificate store.</p>
 <p>By default, uv loads certificates from the bundled <code>webpki-roots</code> crate. The <code>webpki-roots</code> are a reliable set of trust roots from Mozilla, and including them in uv improves portability and performance (especially on macOS).</p>
 <p>However, in some cases, you may want to use the platform's native certificate store, especially if you're relying on a corporate trust root (e.g., for a mandatory proxy) that's included in your system's certificate store.</p>
 <p>May also be set with the <code>UV_NATIVE_TLS</code> environment variable.</p></dd><dt id="uv-python-install--no-bin"><a href="#uv-python-install--no-bin"><code>--no-bin</code></a></dt><dd><p>Do not install a Python executable into the <code>bin</code> directory.</p>
@@ -3502,9 +3502,9 @@ uv python install [OPTIONS] [TARGETS]...
 <p>May also be set with the <code>UV_PROJECT</code> environment variable.</p></dd><dt id="uv-python-install--pypy-mirror"><a href="#uv-python-install--pypy-mirror"><code>--pypy-mirror</code></a> <i>pypy-mirror</i></dt><dd><p>Set the URL to use as the source for downloading PyPy installations.</p>
 <p>The provided URL will replace <code>https://downloads.python.org/pypy</code> in, e.g., <code>https://downloads.python.org/pypy/pypy3.8-v7.3.7-osx64.tar.bz2</code>.</p>
 <p>Distributions can be read from a local directory by using the <code>file://</code> URL scheme.</p>
-<p>May also be set with the <code>UV_PYPY_INSTALL_MIRROR</code> environment variable.</p></dd><dt id="uv-python-install--python-downloads-json-url"><a href="#uv-python-install--python-downloads-json-url"><code>--python-downloads-json-url</code></a> <i>python-downloads-json-url</i></dt><dd><p>URL pointing to JSON of custom Python installations.</p>
+</dd><dt id="uv-python-install--python-downloads-json-url"><a href="#uv-python-install--python-downloads-json-url"><code>--python-downloads-json-url</code></a> <i>python-downloads-json-url</i></dt><dd><p>URL pointing to JSON of custom Python installations.</p>
 <p>Note that currently, only local paths are supported.</p>
-<p>May also be set with the <code>UV_PYTHON_DOWNLOADS_JSON_URL</code> environment variable.</p></dd><dt id="uv-python-install--quiet"><a href="#uv-python-install--quiet"><code>--quiet</code></a>, <code>-q</code></dt><dd><p>Use quiet output.</p>
+</dd><dt id="uv-python-install--quiet"><a href="#uv-python-install--quiet"><code>--quiet</code></a>, <code>-q</code></dt><dd><p>Use quiet output.</p>
 <p>Repeating this option, e.g., <code>-qq</code>, will enable a silent mode in which uv will write no output to stdout.</p>
 </dd><dt id="uv-python-install--reinstall"><a href="#uv-python-install--reinstall"><code>--reinstall</code></a>, <code>-r</code></dt><dd><p>Reinstall the requested Python version, if it's already installed.</p>
 <p>By default, uv will exit successfully if the version is already installed.</p>
@@ -3570,7 +3570,7 @@ uv python upgrade [OPTIONS] [TARGETS]...
 <p>May also be set with the <code>UV_MANAGED_PYTHON</code> environment variable.</p></dd><dt id="uv-python-upgrade--mirror"><a href="#uv-python-upgrade--mirror"><code>--mirror</code></a> <i>mirror</i></dt><dd><p>Set the URL to use as the source for downloading Python installations.</p>
 <p>The provided URL will replace <code>https://github.com/astral-sh/python-build-standalone/releases/download</code> in, e.g., <code>https://github.com/astral-sh/python-build-standalone/releases/download/20240713/cpython-3.12.4%2B20240713-aarch64-apple-darwin-install_only.tar.gz</code>.</p>
 <p>Distributions can be read from a local directory by using the <code>file://</code> URL scheme.</p>
-<p>May also be set with the <code>UV_PYTHON_INSTALL_MIRROR</code> environment variable.</p></dd><dt id="uv-python-upgrade--native-tls"><a href="#uv-python-upgrade--native-tls"><code>--native-tls</code></a></dt><dd><p>Whether to load TLS certificates from the platform's native certificate store.</p>
+</dd><dt id="uv-python-upgrade--native-tls"><a href="#uv-python-upgrade--native-tls"><code>--native-tls</code></a></dt><dd><p>Whether to load TLS certificates from the platform's native certificate store.</p>
 <p>By default, uv loads certificates from the bundled <code>webpki-roots</code> crate. The <code>webpki-roots</code> are a reliable set of trust roots from Mozilla, and including them in uv improves portability and performance (especially on macOS).</p>
 <p>However, in some cases, you may want to use the platform's native certificate store, especially if you're relying on a corporate trust root (e.g., for a mandatory proxy) that's included in your system's certificate store.</p>
 <p>May also be set with the <code>UV_NATIVE_TLS</code> environment variable.</p></dd><dt id="uv-python-upgrade--no-cache"><a href="#uv-python-upgrade--no-cache"><code>--no-cache</code></a>, <code>--no-cache-dir</code>, <code>-n</code></dt><dd><p>Avoid reading from or writing to the cache, instead using a temporary directory for the duration of the operation</p>
@@ -3591,9 +3591,9 @@ uv python upgrade [OPTIONS] [TARGETS]...
 <p>May also be set with the <code>UV_PROJECT</code> environment variable.</p></dd><dt id="uv-python-upgrade--pypy-mirror"><a href="#uv-python-upgrade--pypy-mirror"><code>--pypy-mirror</code></a> <i>pypy-mirror</i></dt><dd><p>Set the URL to use as the source for downloading PyPy installations.</p>
 <p>The provided URL will replace <code>https://downloads.python.org/pypy</code> in, e.g., <code>https://downloads.python.org/pypy/pypy3.8-v7.3.7-osx64.tar.bz2</code>.</p>
 <p>Distributions can be read from a local directory by using the <code>file://</code> URL scheme.</p>
-<p>May also be set with the <code>UV_PYPY_INSTALL_MIRROR</code> environment variable.</p></dd><dt id="uv-python-upgrade--python-downloads-json-url"><a href="#uv-python-upgrade--python-downloads-json-url"><code>--python-downloads-json-url</code></a> <i>python-downloads-json-url</i></dt><dd><p>URL pointing to JSON of custom Python installations.</p>
+</dd><dt id="uv-python-upgrade--python-downloads-json-url"><a href="#uv-python-upgrade--python-downloads-json-url"><code>--python-downloads-json-url</code></a> <i>python-downloads-json-url</i></dt><dd><p>URL pointing to JSON of custom Python installations.</p>
 <p>Note that currently, only local paths are supported.</p>
-<p>May also be set with the <code>UV_PYTHON_DOWNLOADS_JSON_URL</code> environment variable.</p></dd><dt id="uv-python-upgrade--quiet"><a href="#uv-python-upgrade--quiet"><code>--quiet</code></a>, <code>-q</code></dt><dd><p>Use quiet output.</p>
+</dd><dt id="uv-python-upgrade--quiet"><a href="#uv-python-upgrade--quiet"><code>--quiet</code></a>, <code>-q</code></dt><dd><p>Use quiet output.</p>
 <p>Repeating this option, e.g., <code>-qq</code>, will enable a silent mode in which uv will write no output to stdout.</p>
 </dd><dt id="uv-python-upgrade--reinstall"><a href="#uv-python-upgrade--reinstall"><code>--reinstall</code></a>, <code>-r</code></dt><dd><p>Reinstall the latest Python patch, if it's already installed.</p>
 <p>By default, uv will exit successfully if the latest patch is already installed.</p>