textproc/py-mkdocstrings-python-legacy: Update to 0.2.5
- Switch to GitHub for while as the sdist tarball at PyPI doesn't contain all required Python source files.
- Support for Python 3.8 was dropped with this release, thus remove a now obsolete hint regarding the Python version.
Changelog:
https://github.com/mkdocstrings/python-legacy/releases/tag/0.2.5