chore(deps): update grafana/grafana docker tag to v12.3.0 (#1552)

| datasource | package         | from   | to     |
| ---------- | --------------- | ------ | ------ |
| docker     | grafana/grafana | 12.2.1 | 12.3.0 |

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

Author: renovate-sh-app[bot]

.github/workflows/test-mixins.yml

@@ -82,7 +82,7 @@ jobs:
       fail-fast: false
     services:
       grafana:
-        image: grafana/grafana:12.2.1@sha256:35c41e0fd0295f5d0ee5db7e780cf33506abfaf47686196f825364889dee878b
+        image: grafana/grafana:12.3.0@sha256:70d9599b186ce287be0d2c5ba9a78acb2e86c1a68c9c41449454d0fc3eeb84e8
         ports:
           - 3000:3000
         env:

haproxy-mixin/docker-compose.yml

@@ -1,7 +1,7 @@
 version: '3.6'
 services:
   grafana:
-    image: 'grafana/grafana:12.2.1@sha256:35c41e0fd0295f5d0ee5db7e780cf33506abfaf47686196f825364889dee878b'
+    image: 'grafana/grafana:12.3.0@sha256:70d9599b186ce287be0d2c5ba9a78acb2e86c1a68c9c41449454d0fc3eeb84e8'
     environment:
       - 'GF_AUTH_ANONYMOUS_ENABLED=true'
       - 'GF_AUTH_ANONYMOUS_ORG_ROLE=Admin'