Fix Any subclassing in setuptools

[Avasam]

Reference the docutils stub.

As far as I understand, there's no issue with this if docutils isn't installed. And gives proper type when it is.

Fixes 3 subclassing errors (the same error in setuptools, pyinstaller and Pygments stubs)

Ref: #9491

[github-actions]

According to mypy_primer, this change has no effect on the checked open source code. 🤖🎉

[hauntsaninja]

We can remove this comment

[Avasam]

The comment is still true. I think it has value if someone wonders why its in the stub but not in their runtime.

[AlexWaygood]

I sort of wonder if we shouldn't just delete the _distutils directory from our setuptools stubs. The frequency of the changes to that directory (and the leading underscore in the name) indicates to me that the maintainers see the whole directory as an implementation detail, and it just causes work for us to keep the directory up to date. I'm also not sure it's very useful keeping the directory around for type-checking purposes, since setuptools does some terrible importlib hack so that you can import the directory just by doing import distutils at runtime -- so there's little reason to ever import anything from setuptools._distutils directly.

But all that's for another issue/PR discussion.