Description of problem:
Have a machine enter an unhealthy state(stop hyperkube), machine health check triggers remediation, but the node can not be successfully deleted. 

Version-Release number of selected component (if applicable):
openshift-machine-api/jhou-blmrh-w-b-drppv

How reproducible:
Always

Steps to Reproduce:
1. Enable TechPreviewNoUpgrade feature gate

apiVersion: config.openshift.io/v1
kind: FeatureGate
metadata:
  name: cluster
spec:
  featureSet: TechPreviewNoUpgrade

2. Create MHC
apiVersion: healthchecking.openshift.io/v1alpha1
kind: MachineHealthCheck
metadata:
  name: mhc
spec:
  selector:
    matchLabels:
      machine.openshift.io/cluster-api-cluster: jhou-blmrh
      machine.openshift.io/cluster-api-machine-role: worker
      machine.openshift.io/cluster-api-machine-type: worker
      machine.openshift.io/cluster-api-machineset: jhou-blmrh-w-a

3. Create a privileged pod to kill the hyperkube from the node with which MHC is associated.

4. Monitor the machine-healthcheck-controller log

Actual results:

After step 3:
After the node became 'NotReady', a new node is created and added to the cluster. But the unhealthy node can not be deleted. The machine-healthcheck-controller logged an event to be 'deleting' the node, but it never got deleted. 

```
I0826 05:58:58.031790       1 machinehealthcheck_controller.go:242] Initialising remediation logic for machine jhou-blmrh-w-a-l6mjs
I0826 05:58:58.032205       1 machinehealthcheck_controller.go:301] Machine jhou-blmrh-w-a-l6mjs has been unhealthy for too long, deleting
I0826 05:58:58.041371       1 machinehealthcheck_controller.go:90] Reconciling MachineHealthCheck triggered by /jhou-blmrh-w-a-l6mjs.c.openshift-gce-devel.internal
I0826 05:58:58.041422       1 machinehealthcheck_controller.go:113] Node jhou-blmrh-w-a-l6mjs.c.openshift-gce-devel.internal is annotated with machine openshift-machine-api/jhou-blmrh-w-a-l6mjs
I0826 05:58:58.042342       1 machinehealthcheck_controller.go:242] Initialising remediation logic for machine jhou-blmrh-w-a-l6mjs
I0826 05:58:58.042749       1 machinehealthcheck_controller.go:301] Machine jhou-blmrh-w-a-l6mjs has been unhealthy for too long, deleting
```

I thought it might be cause by 1733474, but there isn't any message from the log about the node being drained. However, after annotating the node with machine.openshift.io/exclude-node-draining="", the node got deleted. 

Expected results:
Unhealthy node is deleted.

Additional info: