uv cache prune removes all cached environments

[blueraft]

Summary

Resolves #4802

Test Plan

• cargo test

❯ cargo run -- cache prune -v
Pruning cache at: /Users/ahmedilyas/Library/Caches/uv
No unused entries found
❯ cargo run -- tool run cowsay
warning: `uv tool run` is experimental and may change without warning.
Resolved 1 package in 182ms
Installed 1 package in 20ms
 + cowsay==6.1
usage: Cowsay [-h] [-c CHARACTER] -t TEXT [-v]
Cowsay: error: the following arguments are required: -t/--text
❯ cargo run -- cache prune -v
Pruning cache at: /Users/ahmedilyas/Library/Caches/uv
    0.793440s DEBUG uv_cache Removing dangling cache entry: /Users/ahmedilyas/Library/Caches/uv/environments-v1/095cd7c4c298a0d8
Removed 41 files (143.5KiB)

[charliermarsh]

Thanks!