Merge pull request #42737 from fabianofranz/issues_42697

Automatic merge from submit-queue (batch tested with PRs 42211, 38691, 42737, 42757, 42754)

Fix failing kubectl skew tests

Fixes https://github.com/kubernetes/kubernetes/issues/42697

Skew kubectl tests [are broken](https://k8s-testgrid.appspot.com/release-1.6-upgrade-skew#gce-1.6-master-cvm-kubectl-skew&width=80) in "Simple pod should handle in-cluster config" for trying to copy the `kubectl.sh` script instead of the actual `kubectl` binary.


**Release note**:

```release-note
NONE
```

cluster/kubectl.sh

@@ -68,4 +68,10 @@ if false; then
   echo "Running:" "${kubectl}" "${config[@]:+${config[@]}}" "${@+$@}" >&2
 fi
 
+if [[ "${1:-}" =~ ^(path)$ ]]; then
+  echo "${kubectl}"
+  exit 0
+fi
+
 "${kubectl}" "${config[@]:+${config[@]}}" "${@+$@}"
+