scheduler: drop old 2-week Atomic compose workarounds
    
    Summary:
    all 2-week Atomic composes have been done with Pungi 4 for a
    while now, we don't need these icky workarounds any more. Yay!
    
    Test Plan: Check that job scheduling still works.
    
    Reviewers: jskladan, garretraziel
    
    Reviewed By: garretraziel
    
    Subscribers: tflink
    
    Differential Revision: https://phab.qadevel.cloud.fedoraproject.org/D1021