chore: change setup.py to use optional build_ext option

[CaselIT]

This allows skipping the compilation of the c file if it fails for some reason, like the compiler is missing.
The build will still fail if cython can't generate the c file from the py/pyx file but that should be ok.

The optional keyword is documented here https://setuptools.pypa.io/en/latest/userguide/ext_modules.html#setuptools.Extension

optional (bool) – specifies that a build failure in the extension should not abort the build process, but simply not install the failing extension.

Fixes: #2237

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (6ba54b4) to head (5c70ac4).

Additional details and impacted files

@@            Coverage Diff            @@
##            master     #2242   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           63        63           
  Lines         6852      6852           
  Branches      1260      1260           
=========================================
  Hits          6852      6852           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[vytas7]

Looks good, and I've tested it to work well in different scenarios.
But apparently it is conflicted against master, we need to address these conflicts before merging.

[CaselIT]

Thanks. Will merge with master soon!

[CaselIT]

updated