I tried adding nightlies tox environment for arviz-plots to test future releases.

When running tox -e nightlies, tests importing top level packages of arviz_plots fail with:
AttributeError: module 'matplotlib.style' has no attribute 'core'

following tests fail

• tests/test_backend.py
• tests/test_hypothesis_plots.py
• tests/test_plot_collection.py
• tests/test_plot_matrix.py
• tests/test_plots.py

Reason :

• In the latest matplotlib pre-release (3.11 (dev)), matplotlib.style.core is deprecated.
  Reference
  Next API changes matplotlib.style.core

Questions

• In the places where matplotlib.style.core is called , for example, In arviz_plots/__init__.py, would replacing mplstyle.core.USER_LIBRARY_PATHS and mplstyle.core.reload_library() with mplstyle.USER_LIBRARY_PATHS and mplstyle.reload_library() respectively fix the issue?
• Is it okay to submit the nightlies PR now, even though some tests fail due to recent changes in matplotlib?