feat(container): update image kube-prometheus-stack to v55.8.1 (#1141)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

bootstrap/templates/addons/kube-prometheus-stack/app/helmrelease.yaml.j2

@@ -10,7 +10,7 @@ spec:
   chart:
     spec:
       chart: kube-prometheus-stack
-      version: 55.7.1
+      version: 55.8.1
       sourceRef:
         kind: HelmRepository
         name: prometheus-community