chore(deps): pin dependencies

Signed-off-by: renovate-sh-app[bot] <219655108+renovate-sh-app[bot]@users.noreply.github.com>

Author: renovate-sh-app[bot]

docker-compose.yml

@@ -1,11 +1,11 @@
 services:
   ngrok:
-    image: ngrok/ngrok:latest
+    image: ngrok/ngrok:latest@sha256:50234a734982cdb63d762c2f9983546257f414aa2535917d66ba9433da74f525
     command: http --url=${NGROK_SUBDOMAIN} grafana:3000
     environment:
       NGROK_AUTHTOKEN: ${NGROK_AUTHTOKEN}
   grafana:
-    image: grafana/grafana:main
+    image: grafana/grafana:main@sha256:f0a2f666115f8cdbdff1968f8247e20e26767b97b5bd019edf8d70305cf5e21f
     environment:
       - GF_FEATURE_TOGGLES_ENABLE=provisioning,kubernetesDashboards
       - GF_RENDERING_SERVER_URL=http://renderer:8081/render
@@ -21,7 +21,7 @@ services:
       - ngrok
     restart: unless-stopped
   renderer:
-    image: grafana/grafana-image-renderer:latest
+    image: grafana/grafana-image-renderer:latest@sha256:dc9f4005aa21688fbe408befe1e7a686b0df96b3e378e422d7768fc67a013612
     ports:
       - 8081