Remove requirement on system-release-product
    
    This was added to be overcautious (to ensure that every
    installation of Fedora has at least one of the fedora-release-*
    packages installed). However, this was both redundant (all install
    media includes at least one) and problematic. Since some of the
    fedora-release-$PRODUCT packages have additional explicit deps, it
    was causing a circular dependency loop in certain situations.