Previously, the integration test was always skipped in c9s. Rework it to
pick the correct image manifest based on the running distro and build it
using osbuild.
Pick manifests for the latest distro versions from the upstream
osbuild-composer repository. Use qcow2 image with customizations.
Related: rhbz#2132250
Signed-off-by: Tomáš Hozza <thozza@redhat.com>