Use official crdoc container image

With !164 (merged), a crdoc check is provided with our CI pipeline.

Instead of installing crdoc manually, we should use the official crdoc image recently released.

added modul/infrastructure label

mentioned in merge request !220 (merged)

This is currently blocked as the crdoc image is a distroless one, which is not supported by GitLab.

added Blocked label

See https://github.com/fybrik/crdoc/issues/109

For the record: A non-distroless will became available soon: https://github.com/fybrik/crdoc/pull/115#issuecomment-1020568171

mentioned in commit 2b3bc270

closed with merge request !220 (merged)

removed Blocked label