feat: Add support for Django 6.0

[fsbraun]

This PR adds Django 6.0 compatibility and updates the test matrix.

The key change is that a model's _do_update method requires a 7th positional parameter returning_fields.

charettes/django@55a0073

[codecov]

Codecov Report

❌ Patch coverage is 80.00000% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
django_fsm/__init__.py	80.00%	1 Missing ⚠️

Files with missing lines	Coverage Δ
django_fsm/__init__.py	94.88% <80.00%> (-0.28%)	⬇️

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• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[pfouque]

Not sure yet if it will be released as 4.1 or 5.0 (if we manage to include the admin PR)

Suggested change

	django-fsm-2 4.1.0 unreleased
	django-fsm-2 unreleased

[pfouque]

Thanks for your contribution!
I will merge it despite codecov complaining about the coverage! ;)

[fsbraun]

@pfouque Thanks! The missing coverage line must be spurious. I'm not sure why (aggregation?).

The line claimed uncovered makes the tests pass for Django 6. Maybe there's something with the coverage config?

[pfouque]

Indeed @fsbraun,
The coverage is not consolidated across all versions but runs separately on a single version:

django-fsm-2/.github/workflows/coverage.yml

Line 2 in de01127

As we have just this single version-specific piece of code it's not a big issue.
That's why I merged it anyway

[fsbraun]

@pfouque I would like to advocate for a release...

Django 6.0b1 is out now. We're considering moving our dependencies from django-fsm to django-fsm-2 right now.

What do you think? Is there anyway I can help?