Various `codecov` issues in CI

[TTsangSC]

• For some reasons instead of comparing against the latest main (or at least v5.0.0), codecov is pinned to 60e928f (example 1, example 2).
• The codecov bot prematurely writes the comment (before all the tests are run on all platforms) and only later edits it, and triggers transient false alarms for coverage failure.
• There are duplicate/empty Codecov Upload job steps in the build_binpy_wheels job (example):
  • The first one is skipped because ${{ secrets.CODECOV_TOKEN }} is undefined.
  • The second one reports that no coverage files are found (because cibuildwheel doesn't doesn't run pytest with coverage) and that it thus Failed to run upload-coverage. (This however doesn't cause the pipeline to fail.)
    • This begs the question, should be make CI fail if codecov-action fails (we can use the fail_ci_if_error switch for that)?
• The Codecov Upload job step issues a warning because the file parameter has been superseded by files.

[Erotemic]

Probably can upgrade codecov. Your example of where it is pinned does not seem to be correct.

I'll need to fix the CODECOV_TOKEN, that will be a TODO for me. It should also be easy to update the files in my CI templates.

I don't want coverage to run in cibuildwheel, just when we are testing the built wheels outside of cibuildwheel.

I don't want CI to fail if coverage fails. Coverage is a nice-to-have. This project doesn't have the resources to enforce that it's always working.