koji_parent: resolve TBDs
koji_parent: resolve TBDs

CLOUDBLD-8123

We do not need to inspect a specific platform in these cases (we make
assumptions about base images being roughly equal for all platforms).

The one about parent_images_digests is not relevant, that attribute
still exists and contains the expected data.

Signed-off-by: Adam Cmiel <1217f9865bd733d1bcad0d0d64be310272c5592c@redhat.com>

projectatomic/atomic-reactor,projectatomic/atomic-reactor,fr34k8/atomic-reactor,fr34k8/atomic-reactor