When checking if messages were sent via a rebase, do not run the git hooks
    
    Otherwise, the PR is updated in a separate process that is inaccessible
    from pytest. That process is then the one sending the fedora-messaging
    notifications and suddenly when we check the UI, none of the expected
    notifications were sent.
    
    So instead, we entirely skip the git hooks. The PR gets updated when
    the rebase finishes, in the process run by pytest and we are able to
    check the notifications sent.
    
    Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>