chore: SPEC0 2026 Q2 updates

[flying-sheep]

can’t drop zarr 2 yet since that would mean depending on anndata ≥0.12, and it’s not even time to drop 0.11 yet, I think: 0.11.0 released in November 2024, and all the current SPEC0 deprecations happend latest in June 2024.

what do you think @ilan-gold?

• Closes #
• Tests included or not required because:

• Release notes not necessary because: dep updates

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.06%. Comparing base (1a3141b) to head (a92bcf6).
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4105      +/-   ##
==========================================
- Coverage   79.59%   79.06%   -0.53%     
==========================================
  Files         119      119              
  Lines       12774    12771       -3     
==========================================
- Hits        10167    10097      -70     
- Misses       2607     2674      +67     

Flag	Coverage Δ
hatch-test.low-vers	78.85% <100.00%> (-0.02%)	⬇️
hatch-test.pre	68.99% <100.00%> (-10.47%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/scanpy/preprocessing/_normalization.py	94.66% <ø> (ø)
src/scanpy/preprocessing/_pca/__init__.py	91.97% <100.00%> (+0.46%)	⬆️

... and 7 files with indirect coverage changes

[ilan-gold]

Makes sense, that's the point of all this stuff, to keep us consistent and smooth!

[flying-sheep]

yeah, the gains from dropping anndata 0.11 aren’t big anyway. I think it’s great that we’re in an era of very few anndata compat hacks, because there are changes upcoming!