Simultaneous changes to machine config and Kubernetes version are ignored

[bboreham]

The controller checks if the Kubernetes version is different to that currently installed, and if so goes into a special path to run a kubeadm upgrade:

wksctl/pkg/apis/wksprovider/controller/wksctl/machine_controller.go

Lines 515 to 519 in 96bc981

	func (a *MachineController) kubeadmUpOrDowngrade(machine *clusterv1.Machine, node *corev1.Node, installer *os.OS,
	k8sVersion, planJSON string, ntype recipe.NodeType) error {
	b := plan.NewBuilder()
	upgradeRes, err := recipe.BuildUpgradePlan(installer.PkgType, k8sVersion, ntype)

That code path then builds an upgrade plan using only the Kubernetes version, so, if something else changed in the machine spec at the same time that change will not be applied, it will get lost.