Bump k8s.io/uitls to 8e7ff06

The reason for the bump is the new functionality of the
k8s.io/utils/exec package which allows
- to get a hold of the process' std{out,err} as `io.Reader`s
- to `Start` a process and `Wait` for it

This should help on addressing #70890 by allowing to wrap std{out,err}
of the process to be wrapped with a `io.limitedReader`.

It also updates
- k8s.io/kubernetes/pkg/probe/exec.FakeCmd
- k8s.io/kubernetes/pkg/kubelet/prober.execInContainer
- k8s.io/kubernetes/cmd/kubeadm/app/phases/kubelet.fakeCmd
to implement the changed interface.

The dependency on 'k8s.io/utils/pointer' to the new version has also
been bumped in some staging repos:
- apiserver
- kube-controller-manager
- kube-scheduler

pkg/probe/exec/exec_test.go

@@ -50,8 +50,22 @@ func (f *FakeCmd) SetStdout(out io.Writer) {}
 
 func (f *FakeCmd) SetStderr(out io.Writer) {}
 
+func (f *FakeCmd) SetEnv(env []string) {}
+
 func (f *FakeCmd) Stop() {}
 
+func (f *FakeCmd) Start() error { return nil }
+
+func (f *FakeCmd) Wait() error { return nil }
+
+func (f *FakeCmd) StdoutPipe() (io.ReadCloser, error) {
+	return nil, nil
+}
+
+func (f *FakeCmd) StderrPipe() (io.ReadCloser, error) {
+	return nil, nil
+}
+
 type fakeExitError struct {
 	exited     bool
 	statusCode int