Use kube-prometheus-stack signed OCI Helm chart

Signed-off-by: Stefan Prodan <stefan.prodan@gmail.com>

manifests/monitoring/kube-prometheus-stack/release.yaml

@@ -6,11 +6,13 @@ spec:
   interval: 5m
   chart:
     spec:
-      version: "35.x"
+      version: "41.x"
       chart: kube-prometheus-stack
       sourceRef:
         kind: HelmRepository
         name: prometheus-community
+      verify:
+        provider: cosign
       interval: 60m
   install:
     crds: Create

manifests/monitoring/kube-prometheus-stack/repository.yaml

@@ -4,4 +4,5 @@ metadata:
   name: prometheus-community
 spec:
   interval: 120m
-  url: https://prometheus-community.github.io/helm-charts
+  type: oci
+  url: oci://ghcr.io/prometheus-community/charts