[release-1.15] Remove conversion webhook config in EventPolicy CRD (#8380)

Remove conversion webhook config in EventPolicy CRD

As we don't have multiple EP versions yet, we don't need the conversion webhook configuration in the EventPolicy CRD

Co-authored-by: Christoph Stäbler <cstabler@redhat.com>

Author: knative-prow-robot

config/core/resources/eventpolicy.yaml

@@ -171,11 +171,3 @@ spec:
       - knative
       - eventing
   scope: Namespaced
-  conversion:
-    strategy: Webhook
-    webhook:
-      conversionReviewVersions: ["v1", "v1beta1"]
-      clientConfig:
-        service:
-          name: eventing-webhook
-          namespace: knative-eventing