Remove import re from entrypoint wrapper scripts

[hukkin]

Summary

This removes import re from the wrapper script of installed tools, so that small tools that never import re themselves are allowed to load faster.

This was offered to distlib but was rejected pypa/distlib#239. That discussion includes all the relevant performance measurements for this change.

Here's the corresponding pip issue pypa/pip#13165 and pip PR pypa/pip#13166

The motivation for this change was this discussion on Python Discourse.

Test Plan

Ran

cargo build
./target/debug/uv tool install black
black --version
# observed that installed black runs succesfully
cat ~/.local/bin/black
# observed that the wrapper script no longer imports `re` module

[zanieb]

This seems reasonable to me.

cc @konstin

[charliermarsh]

Yeah this is good.

[konstin]

nice work, thanks!