CI Testing:  Ensure smooth installation od the build under test
    
    Make sure the build under test installs smoothly including the
    multilib subpackages needed for the CI tests.  Use a setup task
    prepare.sh to accomplish that.
    
    The "standard" CI installer installs whole the x86_64 build
    minus glibc-headers-s390, which is a noarch package having
    file conflicts with glibc-headers-x86 (which is another
    noarch subrpm).  The prepare.sh then installs needed i686
    packages.