Avoid canonicalizing user-provided interpreters (#2072)

## Summary

We shouldn't be resolving symlinks on the provided interpreter;
otherwise we break `pyenv`, since running `cargo run pip install mypy
--python .venv/bin/python` will immediately resolve to (e.g.)
`/Users/crmarsh/.pyenv/versions/3.10.2/bin/python3.10`, and pyenv relies
on the path to do its lookups.

Instead, the canonicalizing happens when we query the interpreter
metadata.

Closes https://github.com/astral-sh/uv/issues/2068.

## Test Plan

Ran `cargo run pip install mypy --python .venv/bin/python -v -n` with a
virtualenv created using a pyenv Python; verified that Mypy was
installed into the virtual environment, rather than into the global
environment.

crates/uv-interpreter/src/python_query.rs

@@ -8,6 +8,7 @@ use tracing::{debug, instrument};
 
 use platform_host::Platform;
 use uv_cache::Cache;
+use uv_fs::normalize_path;
 
 use crate::{Error, Interpreter};
 
@@ -63,7 +64,8 @@ pub fn find_requested_python(
         Interpreter::query(&executable, platform.clone(), cache).map(Some)
     } else {
         // `-p /home/ferris/.local/bin/python3.10`
-        let executable = fs_err::canonicalize(request)?;
+        let executable = normalize_path(request);
+
         Interpreter::query(&executable, platform.clone(), cache).map(Some)
     }
 }