bodhi: switch skopeo command
    
    bodhi was using a small script to copy flatpak images from candidate
    registry to registry. This was done because skopeo wasn't able to copy
    multi-arch containers at the time. It has since gained the ability to do
    that and we should stop using the temporary script to do this.
    
    The script doesn't understand the new f39+ flatpaks hash passed to it so
    it fails to push them.
    
    This patch switches bodhi to use normal skopeo and pass it -a which
    should tell it to copy all the arches, not just the one it's running on.
    
    Signed-off-by: Kevin Fenzi <kevin@scrye.com>