updated cluster loader image pull spec to use public registry again

modules/installing-cluster-loader.adoc

@@ -10,5 +10,5 @@
 . To pull the container image, run:
 +
 ----
-$ sudo podman pull registry.svc.ci.openshift.org/ocp/4.5:tests
+$ sudo podman pull quay.io/openshift/origin-tests:4.5
 ----

modules/running-cluster-loader.adoc

@@ -18,9 +18,9 @@ template builds and waits for them to complete:
 +
 ----
 $ sudo podman run -v ${LOCAL_KUBECONFIG}:/root/.kube/config:z -i \
-registry.svc.ci.openshift.org/ocp/4.5:tests /bin/bash -c 'export KUBECONFIG=/root/.kube/config && \
+quay.io/openshift/origin-tests:4.5 /bin/bash -c 'export KUBECONFIG=/root/.kube/config && \
 openshift-tests run-test "[sig-scalability][Feature:Performance] Load cluster \
-should populate the cluster [Slow][Serial] [Suite:openshift]"
+should populate the cluster [Slow][Serial] [Suite:openshift]"'
 ----
 +
 Alternatively, execute Cluster Loader with a user-defined configuration by
@@ -29,10 +29,10 @@ setting the environment variable for `VIPERCONFIG`:
 ----
 $ sudo podman run -v ${LOCAL_KUBECONFIG}:/root/.kube/config:z \
 -v ${LOCAL_CONFIG_FILE_PATH}:/root/configs/:z \
--i registry.svc.ci.openshift.org/ocp/4.5:tests \
+-i quay.io/openshift/origin-tests:4.5 \
 /bin/bash -c 'KUBECONFIG=/root/.kube/config VIPERCONFIG=/root/configs/test.yaml \
 openshift-tests run-test "[sig-scalability][Feature:Performance] Load cluster \
-should populate the cluster [Slow][Serial] [Suite:openshift]"
+should populate the cluster [Slow][Serial] [Suite:openshift]"'
 ----
 +
 In this example, `${LOCAL_KUBECONFIG}` refers to the path to the `kubeconfig` on