Improve %pyproject_check_import newline handling

Add smart newline logic after %pyproject_check_import based on existing
%check section content (adds blank line iff %check was multiline).

This ensures consistent spec file formatting while avoiding unnecessary
blank lines in simple check sections.

Improve remove_remove_bundled_egginfo

Also remove rm -rf %{pypi_name}.egg-info if there is no comment.

Add %pyproject_check_import

Don't process comments

Remove Provides: when adding %py_provides

Limit the sections where we look for certain things

This is a bit faster and saner.

Update to actions/checkout@v4

Setup GitHub Actions (no tests yet)

Packaging

Specs from Fedora