Greenwave policy: skip some known-broken F35 tests from policy
    
    desktop_background tests are known to fail ATM because the F35
    backgrounds don't exist yet, and desktop_update_graphical on
    GNOME is known broken:
    https://bugzilla.redhat.com/show_bug.cgi?id=1995817
    so we add a copy of the policy with those tests left out, to
    avoid all F35 updates failing gating because of these issues.
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>