fix(helm): update chart loki to 6.6.6 (#6712)

| datasource | package | from  | to    |
| ---------- | ------- | ----- | ----- |
| helm       | loki    | 6.6.5 | 6.6.6 |

Co-authored-by: rosey-the-renovator-bot[bot] <98764075+rosey-the-renovator-bot[bot]@users.noreply.github.com>

kubernetes/main/apps/monitoring/loki/app/helmrelease.yaml

@@ -9,7 +9,7 @@ spec:
   chart:
     spec:
       chart: loki
-      version: 6.6.5
+      version: 6.6.6
       sourceRef:
         kind: HelmRepository
         name: grafana-charts