Use %sysusers_requires_compat to match %sysusers_create_compat
    
    The %sysusers_create_compat RPM macro was introduced in commit
    6c2b44a54a5e6c75, so this is meant to match with that.
    
    It's not clear why the 'Requires(pre)' was added to the flatpak-libs
    sub-package in commit b6456a51bb98ec1b when the actual %pre scriptlet
    is part of the main package.  It was likely a mistake.