[Kubernetes] How to delete namespace is Terminating and very stubborn

root@work-space-u20:~/mylab-helm-chart/value-helm# kubectl get ns
NAME                                     STATUS        AGE                             Active        78d
kubecost                                 Terminating   37d

kubectl get namespace kubecost -o json > kubecost.json

kubectl replace --raw "/api/v1/namespaces/kubecost/finalize" -f ./kubecost.json