Automatic merge from submit-queue (batch tested with PRs 62481, 62643, 61877, 62515). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

remove deprecated ExternalID

This field has been deprecated since 1.1. After we remove it we can remove "self delete" from the node's permission set.

@kubernetes/api-reviewers 
@kubernetes/sig-auth-pr-reviews 

fixes https://github.com/kubernetes/kubernetes/issues/61966
part of https://github.com/kubernetes/community/pull/911

```release-note
Kubelets will no longer set `externalID` in their node spec.
```