New release with Django 5.1 support

[felixxm]

Django 5.0 is almost EOL. Can we release a new version with official support for Django 5.1? Humble request 🙇

[browniebroke]

Yes, I think it's time (also Python 3.13 support).

5.2 is coming in a few months, would be nice to have a DRF release before we focus on that.

[browniebroke]

I guess that release should be 3.16. The plan was to release 3.15.3, but IMO there are too much stuff on the branch to be a patch release...

[browniebroke]

I started a milestone and added all the PRs that were merged since the latest release, plus a couple of open ones that I think should be part of it.

I'll leave it for a bit for feedback.