fix regression bug plot_psense_quantities

[aloctavodia]

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📚 Documentation preview 📚: https://arviz-plots--175.org.readthedocs.build/en/175/

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 14.28571% with 12 lines in your changes missing coverage. Please review.

Project coverage is 73.80%. Comparing base (c9d8e20) to head (64dc842).

Files with missing lines	Patch %	Lines
src/arviz_plots/plots/psensequantitiesplot.py	14.28%	12 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #175      +/-   ##
==========================================
- Coverage   73.90%   73.80%   -0.11%     
==========================================
  Files          34       34              
  Lines        3890     3897       +7     
==========================================
+ Hits         2875     2876       +1     
- Misses       1015     1021       +6     

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