Disable docs and tests by default in RHEL builds
    
    This avoided unwanted dependencies,
    particularly python-pretend needed for tests,
    in the RHEL buildroot.
    
    The docs don't pull in any unwanted dependencies,
    but it's easier to disable them together with tests
    and we don't particularly desire python-packaging-docs in RHEL anyway.
    
    Co-Authored-By: Miro Hrončok <miro@hroncok.cz>