Update grafana/grafana Docker tag to v11.6.13

Author: renovate[bot]

docker-compose.yml

@@ -39,7 +39,7 @@ services:
     restart: always
 
   grafana:
-    image: grafana/grafana:11.5.2@sha256:8b37a2f028f164ce7b9889e1765b9d6ee23fec80f871d156fbf436d6198d32b7
+    image: grafana/grafana:11.6.13@sha256:9d7bec5bd872f80d16ea94b03729cd506fb93bbaec807498dc11c94569aeb62c
     volumes:
       - grafana:/var/lib/grafana
       - ./config/grafana/dashboards/:/etc/grafana/dashboards/