Automatic merge from submit-queue

GKE deployment: Kill cluster/gke

kubernetes/test-infra#3983 migrated the remaining GKE jobs using the bash deployment (cluster/gke). All jobs are now on the gke `deployer` in `kubetest`.

Fixes kubernetes/test-infra#3307

```release-note
`cluster/gke` has been removed. GKE end-to-end testing should be done using `kubetest --deployment=gke`
```