fix(helm): update chart loki-simple-scalable to 1.8.8

| datasource | package              | from  | to    |
| ---------- | -------------------- | ----- | ----- |
| helm       | loki-simple-scalable | 1.8.5 | 1.8.8 |

Author: chii-bot[bot]

cluster/apps/monitoring/loki/helm-release.yaml

@@ -9,7 +9,7 @@ spec:
   chart:
     spec:
       chart: loki-simple-scalable
-      version: 1.8.5
+      version: 1.8.8
       sourceRef:
         kind: HelmRepository
         name: grafana-charts