Add PYI lints

[flying-sheep]

OK this is really trivial stuff, I’ll just merge this one

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.52%. Comparing base (6ae9de8) to head (d419e72).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1747      +/-   ##
==========================================
- Coverage   86.99%   84.52%   -2.48%     
==========================================
  Files          40       40              
  Lines        6053     6053              
==========================================
- Hits         5266     5116     -150     
- Misses        787      937     +150     

Files with missing lines	Coverage Δ
src/anndata/_core/anndata.py	83.72% <100.00%> (ø)
src/anndata/_types.py	85.29% <ø> (ø)

... and 8 files with indirect coverage changes