add grafana oci repo

kubernetes/flux/repositories/oci/grafana.yaml

@@ -0,0 +1,15 @@
+---
+# yaml-language-server: $schema=https://raw.githubusercontent.com/fluxcd-community/flux2-schemas/main/ocirepository-source-v1beta2.json
+apiVersion: source.toolkit.fluxcd.io/v1beta2
+kind: OCIRepository
+metadata:
+  name: grafana
+  namespace: flux-system
+spec:
+  interval: 2h
+  layerSelector:
+    mediaType: "application/vnd.cncf.helm.chart.content.v1.tar+gzip"
+    operation: copy
+  url: oci://ghcr.io/grafana/helm-charts/grafana
+  ref:
+    tag: 8.5.5

kubernetes/flux/repositories/oci/kustomization.yaml

@@ -3,4 +3,5 @@
 apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
 resources:
+  - grafana.yaml
   - prometheus-community.yaml