Update kubernetes libs to latest (#2834)

- k8s.io/api v0.28.1
- k8s.io/apiextensions-apiserver v0.28.1
- k8s.io/apimachinery v0.28.1
- k8s.io/client-go v0.28.1
- k8s.io/metrics v0.28.1
- sigs.k8s.io/controller-runtime v0.16.1
- sigs.k8s.io/controller-tools v0.13.0

Signed-off-by: Sanket Sudake <sanketsudake@gmail.com>

pkg/apis/core/v1/httptrigger_webhook.go

@@ -21,6 +21,7 @@ import (
 	"k8s.io/apimachinery/pkg/runtime"
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/webhook"
+	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
 
 	"github.com/fission/fission/pkg/utils/loggerfactory"
 )
@@ -49,31 +50,31 @@ func (r *HTTPTrigger) Default() {
 var _ webhook.Validator = &HTTPTrigger{}
 
 // ValidateCreate implements webhook.Validator so a webhook will be registered for the type
-func (t *HTTPTrigger) ValidateCreate() error {
+func (t *HTTPTrigger) ValidateCreate() (admission.Warnings, error) {
 	httptriggerlog.Debug("validate create", zap.String("name", t.Name))
 	err := t.Validate()
 	if err != nil {
 		err = AggregateValidationErrors("HTTPTrigger", err)
-		return err
+		return nil, err
 	}
-	return nil
+	return nil, nil
 }
 
 // ValidateUpdate implements webhook.Validator so a webhook will be registered for the type
-func (r *HTTPTrigger) ValidateUpdate(old runtime.Object) error {
+func (r *HTTPTrigger) ValidateUpdate(old runtime.Object) (admission.Warnings, error) {
 	httptriggerlog.Debug("validate update", zap.String("name", r.Name))
 	err := r.Validate()
 	if err != nil {
 		err = AggregateValidationErrors("HTTPTrigger", err)
-		return err
+		return nil, err
 	}
 
-	return nil
+	return nil, nil
 }
 
 // ValidateDelete implements webhook.Validator so a webhook will be registered for the type
-func (r *HTTPTrigger) ValidateDelete() error {
+func (r *HTTPTrigger) ValidateDelete() (admission.Warnings, error) {
 	httptriggerlog.Debug("validate delete", zap.String("name", r.Name))
 
-	return nil
+	return nil, nil
 }