Revert "Merge branch 'renovate/zulip-0.x' into 'main'"

This reverts merge request !1017 (merged)

The Zulip chart version 0.3.0 includes the following postgres chart upgrade:

   - name: postgresql
     repository: https://charts.bitnami.com/bitnami
     tags:
       - postgresql
-    version: 10.13.14
+    # Note: values.yaml overwrites posgresql image to zulip/zulip-postgresql:14
+    version: 11.1.22

That's an upgrade that can't be executed automatically. You need to follow this upgrade guide...

For that reason I'm reverting it for now. We should figure out how to do those post/pre-upgrade steps from Flux to make the upgrade succeed.

I think we don't have to follow the upgrade guide to the letter, by the way. Maybe it would even be enough to delete the postgresql helmrelease and then install it again, re-using the old PVC.

Note that we've pinned the postgresql version in the Zulip helm chart, so the postgresql version doesn't actually get updated in this major update. It's mostly the passwords secret that has changed and fails:

root@staging:~# flux suspend -n stackspin-apps hr zulip && flux resume -n stackspin-apps hr zulip
► suspending helmreleases zulip in stackspin-apps namespace
✔ helmreleases suspended
► resuming helmreleases zulip in stackspin-apps namespace
✔ helmreleases resumed
◎ waiting for HelmRelease reconciliation
✗ Helm upgrade failed: execution error at (zulip/charts/postgresql/templates/secrets.yaml:17:24): 
PASSWORDS ERROR: The secret "zulip-postgresql" does not contain the key "postgres-password"