TestWebhook is failing

[barkbay]

TestWebhook failed twice since #7357 has been merged:

=== RUN   TestWebhook
{"log.level":"info","@timestamp":"2023-12-19T19:28:59.269Z","log.logger":"KubeAPIWarningLogger","message":"unknown field \"spec.http.service.metadata.creationTimestamp\"","service.version":"0.0.0-SNAPSHOT+00000000","service.type":"eck","ecs.version":"1.4.0"}
    webhook_test.go:34: 
        	Error Trace:	/go/src/github.com/elastic/cloud-on-k8s/test/e2e/agent/webhook_test.go:34
        	Error:      	"admission webhook \"elastic-agent-validation-v1alpha1.k8s.elastic.co\" denied the request: 
Agent.agent.k8s.elastic.co \"test-webhook\" is invalid: spec: 
Invalid value: v1alpha1.AgentSpec{Version:\"7.17.8\", ElasticsearchRefs:[]v1alpha1.Output(nil), Image:\"\", Config:(*v1.Config)(nil), ConfigRef:(*v1.ConfigSource)(nil), SecureSettings:[]v1.SecretSource(nil), ServiceAccountName:\"\", DaemonSet:(*v1alpha1.DaemonSetSpec)(nil), Deployment:(*v1alpha1.DeploymentSpec)(nil), StatefulSet:(*v1alpha1.StatefulSetSpec)(nil), RevisionHistoryLimit:(*int32)(nil), HTTP:v1.HTTPConfig{Service:v1.ServiceTemplate{ObjectMeta:v1.ObjectMeta{Name:\"\", GenerateName:\"\", Namespace:\"\", SelfLink:\"\", UID:\"\", ResourceVersion:\"\", Generation:0, CreationTimestamp:time.Date(1, time.January, 1, 0, 0, 0, 0, time.UTC), DeletionTimestamp:<nil>, DeletionGracePeriodSeconds:(*int64)(nil), Labels:map[string]string(nil), Annotations:map[string]string(nil), OwnerReferences:[]v1.OwnerReference(nil), Finalizers:[]string(nil), ManagedFields:[]v1.ManagedFieldsEntry(nil)}, Spec:v1.ServiceSpec{Ports:[]v1.ServicePort(nil), Selector:map[string]string(nil), ClusterIP:\"\", ClusterIPs:[]string(nil), Type:\"\", ExternalIPs:[]string(nil), SessionAffinity:\"\", LoadBalancerIP:\"\", LoadBalancerSourceRanges:[]string(nil), ExternalName:\"\", ExternalTrafficPolicy:\"\", HealthCheckNodePort:0, PublishNotReadyAddresses:false, SessionAffinityConfig:(*v1.SessionAffinityConfig)(nil), IPFamilies:[]v1.IPFamily(nil), IPFamilyPolicy:(*v1.IPFamilyPolicy)(nil), AllocateLoadBalancerNodePorts:(*bool)(nil), LoadBalancerClass:(*string)(nil), InternalTrafficPolicy:(*v1.ServiceInternalTrafficPolicy)(nil)}}, TLS:v1.TLSOptions{SelfSignedCertificate:(*v1.SelfSignedCertificate)(nil), Certificate:v1.SecretRef{SecretName:\"\"}}}, Mode:\"\", FleetServerEnabled:false, PolicyID:\"\", KibanaRef:v1.ObjectSelector{Namespace:\"\", Name:\"\", ServiceName:\"\", SecretName:\"\"}, FleetServerRef:v1.ObjectSelector{Namespace:\"\", Name:\"\", ServiceName:\"\", SecretName:\"\"}}:
either daemonSet or deployment or statefulSet must be specified" does not contain "either daemonset or deployment must be specified"
        	Test:       	TestWebhook
--- FAIL: TestWebhook (0.10s)