Eric Mark Martin
967f136564
## Summary In #4085, support was implemented for the `--prefix` option. When using this option, however, a lock is either acquired on the virtualenv or globally, preventing multiple installs to different `--prefix`s from the same interpreter. In this change, acquire the lock on just the prefix in question. ## Test Plan Ran a `uv pip install` with `--prefix` and `RUST_LOG=trace` and observed that the lock was acquired in the prefix.