Catplot fix

[eroell]

• Closes Plotting with using scanpy.pl gives attribute error.  #2680
• Tests included or not required because: this is a longterm fix - failing of this functionality would be captured by existing tests

• Release notes not necessary because:

[codecov]

Codecov Report

Merging #2739 (22e75c6) into master (8369414) will increase coverage by 0.20%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2739      +/-   ##
==========================================
+ Coverage   72.92%   73.13%   +0.20%     
==========================================
  Files         111      111              
  Lines       12134    12134              
==========================================
+ Hits         8849     8874      +25     
+ Misses       3285     3260      -25     

Files	Coverage Δ
scanpy/plotting/_anndata.py	85.02% <ø> (+1.78%)	⬆️

... and 3 files with indirect coverage changes

[eroell]

test_pca failing here and here?

[flying-sheep]

To see tracebacks, you need to scroll up from the end past the enormous warnings list (I’m working on that), then you see the actual error

E           UserWarning: The problem size 5 minus the constraints size 0 is too small relative to the block size 4. Using a dense eigensolver instead of LOBPCG iterations.No output of the history of the iterations.

/opt/hostedtoolcache/Python/3.11.6/x64/lib/python3.11/site-packages/scipy/sparse/linalg/_eigen/lobpcg/lobpcg.py:493: UserWarning

This test has stared to become flaky some time ago, needs some investigation to make this work reliably again.

[eroell]

Yeah noted there is an issue with scipy... Not related to this the single-line update?

[flying-sheep]

Not related to your changes, no.

You can see that e.g. the “PyTest anndata_dev” job succeeded

[eroell]

thx!