Update setup.py for more up-to-date/robust customisation of the build command

[abravalheri]

Closes #1014.

This PR proposes 2 changes:

• Import build from setuptools (motivation in Customising build.sub_commands directly from distutils has been deprecated and is about to be removed #1014)
• Avoid patching of a class attribute of a class that owned by the project (build.sub_commands).

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 76.30%. Comparing base (f200dac) to head (f803ce7).
Report is 2 commits behind head on main.

❗ Current head f803ce7 differs from pull request most recent head bf12c6a. Consider uploading reports for the commit bf12c6a to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1015      +/-   ##
==========================================
- Coverage   76.42%   76.30%   -0.13%     
==========================================
  Files          61       61              
  Lines        8306     8306              
==========================================
- Hits         6348     6338      -10     
- Misses       1958     1968      +10     

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[abravalheri]

ModuleNotFoundError: No module named 'setuptools.command.build'

Maybe this can be fixed by running python -m build instead of python setup.py build (as that would enforce the build requirement already specified in pyproject.toml).