Fix problem with flake B023

[Mr-Geekman]

Before submitting (must do checklist)

• Did you read the contribution guide?
• Did you update the docs? We use Numpy format for all the methods and classes.
• Did you write any new necessary tests?
• Did you update the CHANGELOG?

Proposed Changes

Add checking B023 rule. Fix issues with it.

Closing issues

Closes #782.

[github-actions]

🚀 Deployed on https://deploy-preview-1252--etna-docs.netlify.app

[codecov-commenter]

Codecov Report

Merging #1252 (b4359d4) into master (6396851) will increase coverage by 0.00%.
The diff coverage is 20.00%.

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@@           Coverage Diff           @@
##           master    #1252   +/-   ##
=======================================
  Coverage   57.50%   57.50%           
=======================================
  Files         186      186           
  Lines       10643    10644    +1     
=======================================
+ Hits         6120     6121    +1     
  Misses       4523     4523           

Impacted Files	Coverage Δ
etna/analysis/eda/utils.py	21.42% <0.00%> (ø)
etna/analysis/feature_selection/mrmr_selection.py	32.35% <ø> (ø)
etna/auto/optuna/config_sampler.py	33.33% <25.00%> (+1.07%)	⬆️

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