textproc/py-mkdocstrings-python: Update to 1.10.5

• Switch to GitHub to continue using the test suite, which is currently not included with the recent sdist tarballs. This now makes it possible to run all tests, some of which were not included in the sdist.

Changelog since 1.10.3:

https://github.com/mkdocstrings/python/blob/1.10.5/CHANGELOG.md