Due to DC move (for community cage, moving away from RDU2), testing.stream.centos.org was moved to AWS.

But AWS doesn't offer ppc64le architecture, so we had to just disable ppc64le tests, while waiting for the rdu2 => rdu3 community cage move.

Now that IBM Power is available again, we should just work on needed changes to enable back ppc64le test for all c9s/c10s composes