Use OKD Dockerfile for payload verification keys for release-4.16 (#58619)

Author: Prashanth684

ci-operator/config/openshift/cluster-update-keys/openshift-cluster-update-keys-release-4.16__okd-scos.yaml

@@ -12,7 +12,7 @@ images:
 - build_args:
   - name: TAGS
     value: scos
-  dockerfile_path: Dockerfile.rhel
+  dockerfile_path: Dockerfile
   from: origin_scos-4.16_base-stream9
   to: cluster-update-keys
 promotion: