- update to version 3.2.2:
* Add checklinks tox environment to ensure all links in
documentation are good.
* Refactor extension API documentation (#729).
* Load entry_points (for extensions) only once using
importlib.metadata.
* Do not double escape entities in TOC.
* Correctly report if an extension raises a TypeError (#939).
* Raise a KeyError when attempting to delete a nonexistent key
from the extension registry (#939).
* Remove import of packaging (or pkg_resources fallback) entirely
* Remove setuptools as a run-time dependency (install_required).
- add new requirement importlib-metadata for python < 3.8
- remove setuptools from Requires: dependency dropped by upstream