Update grafana/grafana Docker tag to v12

Author: renovate[bot]

docker-compose/docker-compose-tracing.yml

@@ -13,7 +13,7 @@ services:
       - "3200:3200"   # tempo
 
   grafana:
-    image: grafana/grafana:11.5.2
+    image: grafana/grafana:12.0.0
     volumes:
       - ./tracing/grafana-datasources.yaml:/etc/grafana/provisioning/datasources/datasources.yaml
     environment: