fix: secret store comment

docs/snippets/full-cluster-secret-store.yaml

@@ -49,7 +49,7 @@ spec:
       caProvider:
         # Can be Secret or ConfigMap
         type: "Secret"
-        # This is optional, if not specified will be 'Default'
+        # This is mandatory for ClusterSecretStore and not relevant for SecretStore
         namespace: "my-cert-secret-namespace"
         name: "my-cert-secret"
         key: "cert-key"