fix(docker-image): update pgo docker tag to v5.5.1

| datasource | package                                             | from  | to    |
| ---------- | --------------------------------------------------- | ----- | ----- |
| docker     | registry.developers.crunchydata.com/crunchydata/pgo | 5.5.0 | 5.5.1 |

kubernetes/ironmaiden/apps/database/crunchy-postgres-operator/operator/helmrelease.yaml

@@ -9,7 +9,7 @@ spec:
   chart:
     spec:
       chart: pgo
-      version: 5.5.0
+      version: 5.5.1
       sourceRef:
         kind: HelmRepository
         name: crunchydata