When joining a control plane node and "upgrading" the cluster setup (for
example, to update etcd addresses after adding a new etcd) in the same
playbook run, the node can take a bit of time to become ready after
joining.
This triggers a kubeadm preflight check (ControlPlaneNodesReady) in
kubeadm upgrade, which is run directly after the join tasks.
Add a configurable wait for the control plane node to become Ready to
fix this race condition.
fcecaf6943