Bundling mozjs in both gjs and polkit should make it possible to remove
the system wide mozjs78 package from base RHEL 9, which makes it easier
in the future if we need to update gjs to use newer mozjs. At that
point, we can just update gjs to the new mozjs version it needs and not
have to worry about maintaining a system-wide mozjs78 for all of RHEL 9
lifetime.
Resolves: #1958111
