Windows nodes occasionally fail to join clusters

[nojnhuh]

Which jobs are flaky:

https://storage.googleapis.com/k8s-triage/index.html?pr=1&text=Timed%20out%20waiting%20for%20%5Cd%2B%20(nodes%20to%20be%20created%20for%20MachineDeployment%7Cready%20replicas%20for%20MachinePool)%20.*-win&job=cluster-api-provider-azure

Which tests are flaky:

Testgrid link:

Reason for failure (if possible):

Appears to be a kubeadm failure.

Anything else we need to know:

Looking at a couple of failures:

• CAPI/CAPZ status shows infra succeeded, ~bootstrap completed~ (edit: looks like this actually fails despite the BootstrapSucceeded condition being set on the AzureMachine)
• No logs available for failed Windows machines

/kind flake

[One or more /area label. See https://github.com/kubernetes-sigs/cluster-api/labels?q=area for the list of labels]