Merge pull request #2374 from paraglade/psp_api_update

document update per: https://github.com/rancher/rancher/issues/26194

content/rancher/v2.x/en/security/hardening-2.3.5/_index.md

@@ -514,7 +514,7 @@ rancher_kubernetes_engine_config:
       kind: Group
       name: system:authenticated
     ---
-    apiVersion: extensions/v1beta1
+    apiVersion: policy/v1beta1
     kind: PodSecurityPolicy
     metadata:
       name: restricted