Revert "chore(prometheus): drop dead grafana routes and cert"

This reverts commit 314ec0cda7.

prometheus-stack/k8s/certificates.yaml

@@ -1,5 +1,18 @@
 apiVersion: cert-manager.io/v1
 kind: Certificate
+metadata:
+  name: grafana-prod-tls
+  namespace: prometheus
+spec:
+  secretName: grafana-prod-tls
+  dnsNames:
+    - grafana.forust.xyz
+  issuerRef:
+    name: letsencrypt-prod
+    kind: ClusterIssuer
+---
+apiVersion: cert-manager.io/v1
+kind: Certificate
 metadata:
   name: internal-wildcard-tls
   namespace: prometheus