CI: Add dns-lexicon to tests new things
    
    This tests:
    
    - https://bugzilla.redhat.com/show_bug.cgi?id=1877977
    - https://bugzilla.redhat.com/show_bug.cgi?id=1877978
    
    Unfortunately it is impossible to use this spec to test things on Fedora 31/32,
    so we skip the tests there.
    
    We keep python-requests.spec for now to test Fedora 31/32,
    but it can be removed after Fedora 32 EOL.