Click-extra

- Switch from Poetry to `uv`.
- Drop support for Python 3.8.
- Mark Python 3.13-dev tests as stable.
- Remove dependency on `regex`.

- Fix string interpolation in log message.

- Do not raise error if package version cannot be fetched.

- Do not fail on `docs_update` import if `pygments` is not installed.

- Slim down package by moving unit tests out of the main package.
- Allow reuse of Pytest fixures and marks by other packages.
- Move dependencies extending `pygments`, `sphinx` and `pytest` into optional extra dependencies. Closes {issue}`836`.
- Split `dev` dependency groups into optional `test`, `typing` and `docs` groups.
- Remove direct dependency on `mypy`.
- Allow running tests with Python 3.8 and 3.9 on `macos-14` runners.

- Remove bypass of `cloup.Color` re-import.