fix: add missing spec.interval to cert-manager SSA patch HelmRelease

Agent-Logs-Url: https://github.com/devcm-repo/k3s/sessions/ba2aef3f-dc66-4323-b154-b7acad50a1b1

Co-authored-by: rohow <4090154+rohow@users.noreply.github.com>

flux/infrastructure/infra-devops/post/helmrelease-cert-manager-patch.yaml

@@ -9,6 +9,7 @@ metadata:
   annotations:
     kustomize.toolkit.fluxcd.io/prune: disabled
 spec:
+  interval: 30m
   values:
     prometheus:
       servicemonitor: