Use Box<Path> in lieu of PathBuf for immutable structs (#12346)

## Summary

I don't know if I actually want to commit this, but I did it on the
plane last time and just polished it off (got it to compile) while
waiting to board.

crates/uv-git/src/git.rs

@@ -33,9 +33,9 @@ pub enum GitError {
 
 /// A global cache of the result of `which git`.
 pub static GIT: LazyLock<Result<PathBuf, GitError>> = LazyLock::new(|| {
-    which::which("git").map_err(|e| match e {
+    which::which("git").map_err(|err| match err {
         which::Error::CannotFindBinaryPath => GitError::GitNotFound,
-        e => GitError::Other(e),
+        err => GitError::Other(err),
     })
 });