feat: add environment variable to disable writing installer metadata files (#8877)

## Summary

This change introduces the `UV_NO_INSTALLER_METADATA` environment
variable
as a way to opt out of the extra installer metadata files that `uv` is
creating.

This is important to achieve reproducible builds in distribution
packaging, allowing to replace usage of
[installer](https://pypi.org/project/installer) with `uv pip install`.

At the time of writing these files are:
- `uv_cache.json`
    Contains timestamps which are non-reproducible.
    These hashes also leak in to the `RECORD` file.

- `direct_url.json`
    Contains the path to the installed wheel.
While not non-reproducible it's not required for distribution packaging.

- `INSTALLER`
Again, not non-reproducible, but of no value in distribution packaging.

## Test Plan

Automated test added.

---------

Co-authored-by: Charlie Marsh <charlie.r.marsh@gmail.com>

crates/uv-cli/src/lib.rs

@@ -256,6 +256,10 @@ pub struct GlobalArgs {
     #[arg(global = true, long, env = EnvVars::UV_NO_PROGRESS, value_parser = clap::builder::BoolishValueParser::new())]
     pub no_progress: bool,
 
+    /// Skip writing `uv` installer metadata files (e.g., `INSTALLER`, `REQUESTED`, and `direct_url.json`) to site-packages `.dist-info` directories.
+    #[arg(global = true, long, hide = true, env = EnvVars::UV_NO_INSTALLER_METADATA, value_parser = clap::builder::BoolishValueParser::new())]
+    pub no_installer_metadata: bool,
+
     /// Change to the given directory prior to running the command.
     ///
     /// Relative paths are resolved with the given directory as the base.