Automatic merge from submit-queue
Make "attach" and "exec" rejection in proxy more explicit
```release-note
kubectl proxy changed to now allow urls to pods with "attach" or "exec" in the pod name
```
The more explicit regular expression for rejection makes a possibility of accessing pods (or any other resources) which contain "attach" or "exec" in their names via proxy API. It was not possible before.
Also, the reference for "run" resource was removed, because it doesn't exist in any of k8s APIs currently.
Fixes: #21464
ad7ececcd0