ci: Rework again to use buildah

1 job for master in 38 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
failed #841668
test

00:00:38

 
Name Stage Failure
failed
test Test There has been a runner system failure, please try again
Pulling docker image registry.fedoraproject.org/fedora:30 ...
ERROR: Preparation failed: Error: No such image: registry.fedoraproject.org/fedora:30 (docker.go:205:0s)
Will be retried in 3s ...
Using Docker executor with image registry.fedoraproject.org/fedora:30 ...
WARNING: Container based cache volumes creation is disabled. Will not create volume for "/cache"
Pulling docker image registry.fedoraproject.org/fedora:30 ...
ERROR: Preparation failed: Error: No such image: registry.fedoraproject.org/fedora:30 (docker.go:205:0s)
Will be retried in 3s ...
ERROR: Job failed (system failure): Error: No such image: registry.fedoraproject.org/fedora:30 (docker.go:205:0s)