With uv==0.4.6, running uv python pin 3.12, the made .python-version file does not have trailing whitespace.

This is a little suboptimal because:

• GitHub will show the "missing trailing whitespace" red icon in the diff
• If using https://github.com/pre-commit/pre-commit-hooks's trailing-whitespace, it will give a nonzero return code and autofix the .python-version file to have trailing whitespace

Can we have uv python pin either:

• By default create the .python-version file with trailing whitespace
• Add a configuration/CLI flag --trailing-whitespace for uv python pin to add the trailing whitespace