Remove nessus from cluster configuration

Remove all nessus references: ArgoCD project destination, Istio ambient
enrollment, waypoint gateway, authorization policies, ext-authz policy,
TLS certificate, ingress gateway host, Kyverno exclusion, and Authentik
forward-auth blueprint.

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

infrastructure/istio/manifests/mesh/waypoint-gateways.yaml

@@ -238,20 +238,6 @@ spec:
 ---
 apiVersion: gateway.networking.k8s.io/v1
 kind: Gateway
-metadata:
-  name: waypoint
-  namespace: nessus
-  labels:
-    istio.io/waypoint-for: service
-spec:
-  gatewayClassName: istio-waypoint
-  listeners:
-    - name: mesh
-      port: 15008
-      protocol: HBONE
----
-apiVersion: gateway.networking.k8s.io/v1
-kind: Gateway
 metadata:
   name: waypoint
   namespace: crowdsec