openshift-apps: put fedora-ostree-pruner to sleep
    
    The most recent run caused some data loss [1] so let's put it to
    sleep while we wait for the fix [2] to land.
    
    [1] https://github.com/fedora-silverblue/issue-tracker/issues/405
    [2] https://github.com/ostreedev/ostree/pull/2808