chore(deploy): use OCI registry for cert-manager Helm chart (#2041)

Author: lunarwhite

deploy/helm/openshell/skaffold.yaml

@@ -63,8 +63,7 @@ deploy:
       # when you want cert-manager to manage TLS while certgen handles JWT.
       # Requires cert-manager CRDs to be installed in the cluster first.
       #- name: cert-manager
-      #  repo: https://charts.jetstack.io
-      #  remoteChart: cert-manager
+      #  remoteChart: oci://quay.io/jetstack/charts/cert-manager
       #  version: v1.20.2
       #  namespace: cert-manager
       #  createNamespace: true

docs/kubernetes/managing-certificates.mdx

@@ -26,12 +26,11 @@ cert-manager precedence applies even if `pkiInitJob.enabled` remains true.
 
 ## Install cert-manager
 
-Add the Jetstack Helm repository and install cert-manager with CRD support enabled:
+Install cert-manager from the OCI registry with CRD support enabled:
 
 ```shell
-helm repo add jetstack https://charts.jetstack.io
-helm repo update
-helm upgrade --install cert-manager jetstack/cert-manager \
+helm upgrade --install cert-manager oci://quay.io/jetstack/charts/cert-manager \
+  --version v1.20.2 \
   --namespace cert-manager \
   --create-namespace \
   --set crds.enabled=true \