feat(authentication): add manifest for disabling self-provisioning

Author: jeichler

content/cluster-configuration/authentication/redhat-sso.md

@@ -70,3 +70,14 @@ oc delete secrets kubeadmin -n kube-system
 oc adm policy remove-cluster-role-from-group self-provisioner system:authenticated system:authenticated:oauth
 ```
 
+Or the respective manifest:
+
+```yaml
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  annotations:
+    rbac.authorization.kubernetes.io/autoupdate: "false"
+  name: self-provisioners
+subjects: null
+```