Fix bug when setting some plot_kwargs to false

[aloctavodia]

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📚 Documentation preview 📚: https://arviz-plots--134.org.readthedocs.build/en/134/

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 30.76923% with 9 lines in your changes missing coverage. Please review.

Project coverage is 78.96%. Comparing base (eafb6e0) to head (8174d6f).

Files with missing lines	Patch %	Lines
src/arviz_plots/plots/psensequantitiesplot.py	0.00%	7 Missing ⚠️
src/arviz_plots/plots/pavacalibrationplot.py	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #134      +/-   ##
==========================================
- Coverage   78.98%   78.96%   -0.03%     
==========================================
  Files          28       28              
  Lines        3265     3266       +1     
==========================================
  Hits         2579     2579              
- Misses        686      687       +1     

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