remove istioctl copying from final publish step (#4586)
remove istioctl copying from final publish step (#4586)

Automatic merge from submit-queue.

remove istioctl copying from final publish step

we no longer need to copy istioctl into release directory since they are present in the tar/zip files
istio/istio,geeknoid/istio,geeknoid/istio,frankbu/istio,istio/istio,smawson/istio,geeknoid/istio,smawson/istio,frankbu/istio,istio/istio,frankbu/istio,istio/istio,geeknoid/istio,geeknoid/istio,smawson/istio,geeknoid/istio,istio/istio,frankbu/istio,frankbu/istio,smawson/istio,frankbu/istio,smawson/istio,smawson/istio