Remove old Istio VirtualService for Ceph dashboard

The dashboard now uses the Envoy edge gateway via HTTPRoute. The old
Istio VirtualService was causing DNS to point at the wrong gateway IP.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

infrastructure/rook-ceph/manifests/istio-virtualservice.yaml

@@ -1,17 +0,0 @@
-apiVersion: networking.istio.io/v1beta1
-kind: VirtualService
-metadata:
-  name: ceph-dashboard
-  namespace: rook-ceph
-spec:
-  hosts:
-    - ceph.kube.huskypup.net
-  gateways:
-    - istio-system/edge
-  http:
-    - timeout: 3600s
-      route:
-        - destination:
-            host: rook-ceph-mgr-dashboard.rook-ceph.svc.cluster.local
-            port:
-              number: 8443