chore(deps): update postgres-cluster docker tag to v7.7.0 (#4140)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [postgres-cluster](https://github.com/cloudnative-pg/cloudnative-pg) | minor | `7.6.0` → `7.7.0` |

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Reviewed-on: #4140
Co-authored-by: Renovate Bot <renovate-bot@alexlebens.net>
Co-committed-by: Renovate Bot <renovate-bot@alexlebens.net>

clusters/cl01tl/helm/stalwart/Chart.lock

@@ -4,12 +4,12 @@ dependencies:
   version: 4.6.2
 - name: postgres-cluster
   repository: oci://harbor.alexlebens.net/helm-charts
-  version: 7.6.0
+  version: 7.7.0
 - name: redis-replication
   repository: oci://harbor.alexlebens.net/helm-charts
   version: 1.0.4
 - name: volsync-target
   repository: oci://harbor.alexlebens.net/helm-charts
   version: 0.7.0
-digest: sha256:78397bba7be9d177cf3310bea1c5d7873f26c8eac19236d115b27cf4c2330bf1
-generated: "2026-02-13T19:45:22.903534107Z"
+digest: sha256:4f558802a00c3c8511762197f73c8e179c3b72218a805d7a7fe8e31913c54a37
+generated: "2026-02-21T20:05:54.93683159Z"