style: pandas lint

[flying-sheep]

See scverse/anndata#1241. Choosing between .array and .to_numpy() isn’t trivial, so I want to make sure this is flagged in future PRs and no .values slips through.

• Closes #
• Tests included or not required because:

• Release notes not necessary because: style only

[codecov]

Codecov Report

❌ Patch coverage is 87.50000% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 78.60%. Comparing base (8ba90cf) to head (be10189).
⚠️ Report is 1 commits behind head on main.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/scanpy/_utils/__init__.py	66.66%	5 Missing ⚠️
src/scanpy/external/exporting.py	0.00%	1 Missing ⚠️
src/scanpy/plotting/_anndata.py	50.00%	1 Missing ⚠️
src/scanpy/plotting/_tools/paga.py	87.50%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4080      +/-   ##
==========================================
+ Coverage   78.52%   78.60%   +0.08%     
==========================================
  Files         118      118              
  Lines       12755    12753       -2     
==========================================
+ Hits        10016    10025       +9     
+ Misses       2739     2728      -11     

Flag	Coverage Δ
hatch-test.low-vers	77.91% <84.37%> (+<0.01%)	⬆️
hatch-test.pre	78.49% <87.50%> (+15.12%)	⬆️

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

Files with missing lines	Coverage Δ
...c/scanpy/experimental/pp/_highly_variable_genes.py	94.23% <100.00%> (ø)
src/scanpy/external/pp/_hashsolo.py	88.03% <100.00%> (ø)
src/scanpy/get/get.py	92.85% <100.00%> (ø)
src/scanpy/plotting/_dotplot.py	94.87% <100.00%> (ø)
src/scanpy/plotting/_stacked_violin.py	85.78% <100.00%> (-0.08%)	⬇️
src/scanpy/plotting/_tools/__init__.py	76.17% <100.00%> (ø)
src/scanpy/plotting/_tools/scatterplots.py	83.48% <100.00%> (ø)
src/scanpy/plotting/_utils.py	78.85% <100.00%> (ø)
src/scanpy/preprocessing/_combat.py	88.88% <100.00%> (+0.16%)	⬆️
src/scanpy/preprocessing/_highly_variable_genes.py	95.07% <100.00%> (ø)
... and 10 more

... and 1 file with indirect coverage changes