Update yamllint to fix dependency issue

I think this still validates everything we need it to

ansible/roles/forrest/files/grafana/docker-compose.yml

@@ -4,7 +4,7 @@ services:
   grafana:
     image: grafana/grafana:latest
     environment:
-      - TZ={{ TZ }}
+      - TZ={{ timezone }}
       - GF_DATABASE_URL=postgres://grafana:grafana@db/grafana
       - GF_RENDERING_SERVER_URL=http://renderer:8081/render
       - GF_RENDERING_CALLBACK_URL=http://grafana:3000/
@@ -42,7 +42,7 @@ services:
     image: grafana/grafana-image-renderer:latest
     restart: unless-stopped
     environment:
-      - BROWSER_TZ={{ TZ }}
+      - BROWSER_TZ={{ timezone }}
 
 
 networks: