deprecate Python 3.9

[bendichter]

EOL was Oct 31 2025

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.21%. Comparing base (e00ffc0) to head (419cbf2).
⚠️ Report is 1 commits behind head on dev.

Additional details and impacted files

@@           Coverage Diff           @@
##              dev    #2141   +/-   ##
=======================================
  Coverage   95.21%   95.21%           
=======================================
  Files          29       29           
  Lines        2945     2945           
  Branches      757      757           
=======================================
  Hits         2804     2804           
  Misses         84       84           
  Partials       57       57           

Flag	Coverage Δ
integration	72.93% <ø> (ø)
unit	85.16% <ø> (ø)

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[stephprince]

One other suggestion otherwise looks good to me! I will let @rly add any comments and can then update the PR required checks to use the new minimum test workflow versions before merging.

[rly]

Thanks for this PR @bendichter ! It looks all good to me. This should be in a minor release. We should also explore adding Python 3.14 support in a separate PR.

[rly]

We'll make a bugfix release imminently and then do a minor release with this PR deprecating python 3.9 shortly after

[h-mayorquin]

Python 3.9 did not allow me to use typing constructions on #2164

b932db4

[bendichter]

@rly this is ready to go

[rly]

Can you update the workflows so that all minimum tests on macos use macos-15-intel, and set the minimum h5py version to 3.6.0 (same as hdmf)?