Drop support for Python 3.9

[claudep]

Python 3.9 is EOL end of October 2025.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 74.27%. Comparing base (2f0e95f) to head (cabf152).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #789   +/-   ##
=======================================
  Coverage   74.27%   74.27%           
=======================================
  Files          26       26           
  Lines        1691     1691           
=======================================
  Hits         1256     1256           
  Misses        435      435           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

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

[claudep]

I would appreciate an approval here. I would like to see this in the next release.

[jnovinger]

I feel like CI might pass on this one once #792 is merged and this is rebased on it. No?

[claudep]

You were right, only the approval is missing.