fix(helm): update chart kube-prometheus-stack to 81.5.1

Author: roybatty-bot[bot]

cluster/apps/monitoring/prometheus/app/helmrelease.yaml

@@ -10,7 +10,7 @@ spec:
   chart:
     spec:
       chart: kube-prometheus-stack
-      version: 81.5.0
+      version: 81.5.1
       sourceRef:
         kind: HelmRepository
         name: prometheus-community