How to read `--python-version` from file with `pip-compile` hook

`uv pip compile` doesn't read `pyproject.toml` or `.python-version` to default the `--python-version` flag (https://github.com/astral-sh/uv/issues/9581). Running `uv pip compile --python-version=$(cat .python-version)` is an acceptable workaround, but this doesn't work using the `pip-compile` pre-commit hook because pre-commit just passes the arguments as literal strings and `uv pip compile` can't do the variable expansion dynamically.

Are there any recommended ways to not have to hardcode `--python-version` here?

Start by reviewing the pip-compile pre-commit hook invocation and how pre-commit passes arguments to `uv pip compile`. Compare that behavior with the `.python-version` workaround and determine whether a supported configuration can avoid hardcoding `--python-version`; done means documenting or validating a working approach.

Written by the indexing model from the issue text.