Update python for the flake8 workflow

[JeanChristopheMorinPerso]

GitHub continues to be hostile to users and dropped python 3.7 support in the actions/setup-python action. So this PR updates python to 3.11 for the flake8 workflow.

Other changes are related to newer flake8 versions.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 58.58%. Comparing base (fe13e89) to head (8ecd624).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1847   +/-   ##
=======================================
  Coverage   58.58%   58.58%           
=======================================
  Files         126      126           
  Lines       17207    17207           
  Branches     3014     3014           
=======================================
  Hits        10080    10080           
  Misses       6474     6474           
  Partials      653      653           

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