Enable Python 3.13 in tests

[kklein]

Checklist

• Added a CHANGELOG.rst entry

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.88%. Comparing base (ce01372) to head (e4e1804).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #124   +/-   ##
=======================================
  Coverage   91.88%   91.88%           
=======================================
  Files          16       16           
  Lines        1960     1960           
=======================================
  Hits         1801     1801           
  Misses        159      159           

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[FrithjofWinkelmannQC]

LGTM :)
Will adress the flaky tests in another PR