Fix warnings

[PGijsbers]

Minor changes to avoid warnings, or explicitly ignore them in for pytest with motivation.

[github-actions]

Thank you for the pull request! 🙏
If CI reports any errors please address them.
If you believe the errors are unrelated to your PR, please state why.
This will make it easier for the maintainers to assess your PR :)

[codecov]

Codecov Report

Merging #170 (db74a53) into master (556d601) will increase coverage by 2.54%.
The diff coverage is 77.77%.

@@            Coverage Diff             @@
##           master     #170      +/-   ##
==========================================
+ Coverage   65.72%   68.26%   +2.54%     
==========================================
  Files          45       45              
  Lines        2188     2187       -1     
==========================================
+ Hits         1438     1493      +55     
+ Misses        750      694      -56     

Flag	Coverage Δ
unit-tests	68.26% <77.77%> (+2.54%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
gama/GamaClassifier.py	54.34% <0.00%> (ø)
gama/configuration/classification.py	100.00% <ø> (ø)
gama/configuration/regression.py	100.00% <ø> (ø)
gama/configuration/testconfiguration.py	100.00% <ø> (ø)
gama/postprocessing/ensemble.py	43.34% <66.66%> (+21.21%)	⬆️
gama/genetic_programming/components/individual.py	89.85% <100.00%> (ø)
...a/genetic_programming/components/primitive_node.py	95.83% <100.00%> (+2.08%)	⬆️
gama/logging/GamaReport.py	91.35% <100.00%> (+1.35%)	⬆️
gama/utilities/evaluation_library.py	82.53% <0.00%> (+0.79%)	⬆️
... and 3 more

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more