chore: use scverse-misc’s @deprecated

[flying-sheep]

• Closes #
• Tests included or not required because:

• Release notes not necessary because: only backend / minor docs changes

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.59%. Comparing base (396b665) to head (120aa9d).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4096      +/-   ##
==========================================
- Coverage   79.60%   79.59%   -0.02%     
==========================================
  Files         119      119              
  Lines       12778    12774       -4     
==========================================
- Hits        10172    10167       -5     
- Misses       2606     2607       +1     

Flag	Coverage Δ
hatch-test.low-vers	78.87% <100.00%> (+0.01%)	⬆️
hatch-test.pre	79.45% <100.00%> (-0.01%)	⬇️

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

Files with missing lines	Coverage Δ
src/scanpy/_compat.py	85.71% <100.00%> (-1.33%)	⬇️
src/scanpy/_settings/__init__.py	91.72% <100.00%> (+0.06%)	⬆️
src/scanpy/_settings/verbosity.py	81.57% <100.00%> (+0.49%)	⬆️
src/scanpy/datasets/_datasets.py	92.02% <100.00%> (+0.05%)	⬆️
src/scanpy/external/pl.py	29.21% <100.00%> (-0.79%)	⬇️
src/scanpy/external/pp/__init__.py	100.00% <100.00%> (ø)
src/scanpy/logging.py	97.29% <100.00%> (ø)
src/scanpy/plotting/__init__.py	100.00% <100.00%> (ø)
src/scanpy/plotting/_tools/scatterplots.py	83.41% <100.00%> (ø)
src/scanpy/readwrite.py	81.27% <100.00%> (+0.04%)	⬆️
... and 1 more

... and 1 file with indirect coverage changes

[ilan-gold]

Failing CI but the code looks right!