working_dir has Optional type when it can't be None

[Sineaggi]

In https://github.com/gitpython-developers/GitPython/blob/main/git/repo/base.py#L285 working_dir is never assigned to None, which means it type shouldn't be marked as Optional.

[Byron]

What happens when the repository is bare? Then by definition it has no working dir, and I don't think working_dir is populated anyway.