chore(deps): update ghcr.io/mend/renovate-ce docker tag to v13.4.0

library/compose/renovate/compose.yaml.j2

@@ -1,7 +1,7 @@
 ---
 services:
   {{ service_name }}:
-    image: ghcr.io/mend/renovate-ce:13.3.0-full
+    image: ghcr.io/mend/renovate-ce:13.4.0-full
     {#
       If not in swarm mode, apply container name and restart policy
     #}