[HOLD] Start 2.9.0-dev0

[IAlibay]

If this comes back not red (except the 3.9 runners.. they are still pulling old MDAnalysis): https://github.com/MDAnalysis/mdanalysis/actions/runs/12039544989/job/33567570077

Then we're good to go.

PR Checklist

• CHANGELOG updated?

Developers certificate of origin

• I certify that this contribution is covered by the LGPLv2.1+ license as defined in our LICENSE and adheres to the Developer Certificate of Origin.

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📚 Documentation preview 📚: https://mdanalysis--4803.org.readthedocs.build/en/4803/

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 93.65%. Comparing base (46be788) to head (d62dc0a).
Report is 1 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #4803      +/-   ##
===========================================
- Coverage    93.67%   93.65%   -0.02%     
===========================================
  Files          177      189      +12     
  Lines        21742    22808    +1066     
  Branches      3055     3055              
===========================================
+ Hits         20366    21360     +994     
- Misses         928     1001      +73     
+ Partials       448      447       -1     

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[orbeckst]

lgtm

[IAlibay]

Alright I'm calling this one as "ok" - only thing that's failing is the py3.9 pipelines and they are running on MDA 2.7.0.