fixed postgresql requirement

chart/requirements.lock

 dependencies:
 - name: postgresql
-  repository: https://kubernetes-charts.storage.googleapis.com/
+  repository: https://gitlab-org.gitlab.io/cluster-integration/helm-stable-archive
   version: 0.7.1
-digest: sha256:358ce85fe4d3461ea6bb96713470a80de9c1324214a2e6f97d800298c02530e2
-generated: 2017-08-28T15:22:30.690341342-05:00
+digest: sha256:0a7e2f279e3b8063cfe6365a56601227ff8934fa70a0434df0485bce9590be56
+generated: "2020-10-21T09:35:20.464079556+07:00"

chart/requirements.yaml

 dependencies:
+  # This is a legacy in-cluster PostgreSQL dependency that is no longer used for newer installations.
+  # We can remove this dependency when we drop support for the legacy instances.
   - name: postgresql
     version: "0.7.1"
-    repository: "https://kubernetes-charts.storage.googleapis.com/"
+    repository: "@stable-archive"
     condition: postgresql.enabled