chore(prometheus): drop dead grafana routes and cert

No grafana is deployed from this stack, so grafana-prod/grafana-local only ever served 503s. Live objects already deleted directly; this keeps git from resurrecting them on the next deploy.

prometheus-stack/k8s/ingress.yaml

@@ -1,36 +0,0 @@
-apiVersion: traefik.io/v1alpha1
-kind: IngressRoute
-metadata:
-  name: grafana-prod
-  namespace: prometheus
-spec:
-  entryPoints:
-    - websecure
-  routes:
-    - match: Host(`grafana.forust.xyz`)
-      kind: Rule
-      middlewares:
-        - name: crowdsec-bouncer
-          namespace: crowdsec
-      services:
-        - name: prometheus-stack-grafana
-          port: 80
-  tls:
-    secretName: grafana-prod-tls
----
-apiVersion: traefik.io/v1alpha1
-kind: IngressRoute
-metadata:
-  name: grafana-local
-  namespace: prometheus
-spec:
-  entryPoints:
-    - websecure
-  routes:
-    - match: Host(`grafana.workstation.internal`) || Host(`grafana.gigaforust.internal`)
-      kind: Rule
-      services:
-        - name: prometheus-stack-grafana
-          port: 80
-  tls:
-    secretName: internal-wildcard-tls