Backport PR #3864 on branch 1.11.x (fix: various DPT plot fixes)

[flying-sheep]

Backports #3864

[codecov]

Codecov Report

❌ Patch coverage is 84.61538% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 75.73%. Comparing base (3a9a0ec) to head (3d1623f).
⚠️ Report is 1 commits behind head on 1.11.x.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/scanpy/plotting/_tools/__init__.py	66.66%	1 Missing ⚠️
src/scanpy/plotting/_utils.py	88.88%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           1.11.x    #3869      +/-   ##
==========================================
+ Coverage   75.23%   75.73%   +0.50%     
==========================================
  Files         116      116              
  Lines       13106    13110       +4     
==========================================
+ Hits         9860     9929      +69     
+ Misses       3246     3181      -65     

Files with missing lines	Coverage Δ
src/scanpy/tools/_dpt.py	65.69% <100.00%> (+7.17%)	⬆️
src/scanpy/plotting/_tools/__init__.py	76.76% <66.66%> (+0.87%)	⬆️
src/scanpy/plotting/_utils.py	67.01% <88.88%> (+6.42%)	⬆️