devel/py-python-gitlab: Update to 3.0.0

• Update to 3.0.0 [1]
• Add missing dist file docs/changelog.md [2]
• Add patch to fix sphinx 4.1 feature autodoc_typehints both [3][4]

[1] https://github.com/python-gitlab/python-gitlab/releases/tag/v3.0.0
[2] https://github.com/python-gitlab/python-gitlab/pull/1813
[3] https://www.sphinx-doc.org/en/master/usage/extensions/autodoc.html
[4] https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=257116

PR: 261026
Reported by: Derek Schrock (maintainer)