Pass _NOOBSOLETEBUILD when scheduling update jobs
    
    openQA has a feature where, when you POST a new item for test,
    it will cancel all running tests for the same DISTRI, VERSION,
    FLAVOR and ARCH. This is obviously not desirable for update
    tests; tests for update X shouldn't "obsolete" tests for update
    Y. So, pass the magic `_NOOBSOLETEBUILD` setting which disables
    this behaviour when creating update jobs.