chore(deps): update postgresql docker tag to v18.5.6 (#53)

Chart.yaml

@@ -32,7 +32,7 @@ dependencies:
   # https://github.com/bitnami/charts/blob/main/bitnami/postgresql
   - name: postgresql
     repository: oci://registry-1.docker.io/bitnamicharts
-    version: 18.5.5
+    version: 18.5.6
     condition: postgresql.enabled
   # https://github.com/bitnami/charts/blob/main/bitnami/postgresql-ha/Chart.yaml
   - name: postgresql-ha