Fix panic in the TestBrokerNamespaceDefaulting (#4711)
Fix panic in the TestBrokerNamespaceDefaulting (#4711)

Error was:

knative.dev/eventing/test/e2e.webhookObservedBrokerUpdateFromDeliverySpec(...)
	/home/runner/work/eventing/eventing/src/knative.dev/eventing/test/e2e/broker_defaults_webhook_test.go:179
knative/eventing,knative/eventing