Setuptools includes type info by default now, update docs accordingly

**Documentation**

With setuptools v69.0.0, [type info is included in packages by default](https://setuptools.pypa.io/en/stable/history.html#v69-0-0). This feature is still experimental, but worth keeping an eye on so [the relevant mypy docs ](https://mypy.readthedocs.io/en/stable/installed_packages.html#creating-pep-561-compatible-packages) can be updated. 