fix: update docker image nginx to 1.27.3

| datasource | package | from   | to     |
| ---------- | ------- | ------ | ------ |
| docker     | nginx   | 1.27.2 | 1.27.3 |

k8s/clusters/cluster-0/manifests/selfhosted/nextcloud/helm-release.yaml

@@ -163,7 +163,7 @@ spec:
       enabled: true
       image:
         repository: nginx
-        tag: "1.27.2"
+        tag: "1.27.3"
       config:
         default: true
       resources: