Update postgres-cluster Docker tag to v6.13.0 (#1698)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [postgres-cluster](https://github.com/cloudnative-pg/cloudnative-pg) | minor | `6.12.0` -> `6.13.0` |

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Reviewed-on: #1698
Co-authored-by: Renovate Bot <renovate-bot@alexlebens.net>
Co-committed-by: Renovate Bot <renovate-bot@alexlebens.net>

clusters/cl01tl/monitoring/gatus/Chart.yaml

@@ -22,7 +22,7 @@ dependencies:
     version: 1.4.2
   - name: postgres-cluster
     alias: postgres-17-cluster
-    version: 6.12.0
+    version: 6.13.0
     repository: oci://harbor.alexlebens.net/helm-charts
 icon: https://cdn.jsdelivr.net/gh/selfhst/icons/png/gatus.png
 appVersion: v5.12.0

clusters/cl01tl/monitoring/grafana-operator/Chart.yaml

@@ -21,7 +21,7 @@ dependencies:
     repository: https://grafana.github.io/helm-charts
   - name: postgres-cluster
     alias: postgres-17-cluster
-    version: 6.12.0
+    version: 6.13.0
     repository: oci://harbor.alexlebens.net/helm-charts
 icon: https://cdn.jsdelivr.net/gh/selfhst/icons/png/grafana.png
 appVersion: v5.18.0