devel/py-python-gitlab: Update to 5.1.0
Add GRAPHQL to default option and remove GRAPHQL_BROKEN.
Use DISTNAME= instead of ?=.
Patch CHANGELOG.md to better format.
Changelog:
https://github.com/python-gitlab/python-gitlab/releases/tag/v5.1.0
PR: 283033
Approved by: submitter is maintainer