Fix pylint and pickling issue

[ahartikainen]

Description

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

[codecov]

Codecov Report

Merging #1743 (c6b5b3b) into main (ae83908) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #1743   +/-   ##
=======================================
  Coverage   90.87%   90.87%           
=======================================
  Files         109      109           
  Lines       11844    11844           
=======================================
  Hits        10763    10763           
  Misses       1081     1081           

Impacted Files	Coverage Δ
arviz/data/inference_data.py	83.71% <100.00%> (ø)
arviz/data/io_pyro.py	96.24% <100.00%> (ø)

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[canyon289]

This has a new issue now right? PyMC is causing some caching problem?

[ahartikainen]

Apparently. Usually these fix themselves in a day or two.

[canyon289]

I ran tests locally in multiple envs and they passed so rerunning here

[canyon289]

Noting here as well. PyMC changed to cloud pickle which points to why pickle is failing. Should we make the switch as well?

https://github.com/pymc-devs/pymc3/blob/main/pymc3/tests/test_model.py#L410

[canyon289]

Alright I dont have enough time to figure out mypy but propose we merge this so we can unblock all other PRs. Thoughts?

[canyon289]

We can delete the "manual" install method now.