textproc/py-mkdocstrings: Update to 0.30.0
- Remove no longer required workaround for remnant mypy files.
- Adjust the test suite as well as one more test now works with newer versions of py-markdown.
Changelog:
https://github.com/mkdocstrings/mkdocstrings/releases/tag/0.30.0
MFH: 2025Q3
(cherry picked from commit e4d1fc148e59ba312ef6f01753121b8a26dd282e)