Update active tests

[OriolAbril]

Dropping beanmachine we also are able to use latest black, instead of the over a year old version beanmachine pulls as runtime dependency.

I also want to fix the readthedocs build in this PR.

Checklist

• [ ] Follows official PR format
• [ ] Includes a sample plot to visually illustrate the changes (only for plot-related functions)
• [ ] New features are properly documented (with an example if appropriate)?
• [ ] Includes new or updated tests to cover the new feature
• [ ] Code style correct (follows pylint and black guidelines)
• [ ] Changes are listed in changelog

---

:books: Documentation preview :books:: https://arviz--2290.org.readthedocs.build/en/2290/

[codecov[bot]]

Codecov Report

Attention: 3 lines in your changes are missing coverage. Please review.

Comparison is base (eb88f3a) 86.89% compared to head (cb21419) 86.70%. Report is 2 commits behind head on main.

Files	Patch %	Lines
arviz/data/io_pyjags.py	0.00%	2 Missing :warning:
arviz/data/io_beanmachine.py	0.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #2290 +/- ## ========================================== - Coverage 86.89% 86.70% -0.20% ========================================== Files 122 122 Lines 12628 12640 +12 ========================================== - Hits 10973 10959 -14 - Misses 1655 1681 +26 ```

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