graduate "kubeadm init phase kubelet-finalize experimental-cert-rotation"

[neolit123]

the kubeadm init phase kubelet-finalize experimental-cert-rotation phase of kubeadm init is responsible for modifying the initial kubelet.conf during primary node bootstrap to point to the /var/lib/kubelet/pki cert and key PEM file. it happens after the first kubelet in the cluster self-bootstraps.

we originally added this extra phase as experimental as we wasn't sure if this is what we want. now i regret this decision as it would require one release deprecation window vs just a EXPERIMENTAL note.

1.31

• add a new phase cert-rotation that does that same and mark experimental-cert-rotation as deprecated. there has to be a way to only execute one of them when doing "all"
• kubeadm: mark the phase 'experimental-cert-rotation' as deprecated kubernetes#124419

1.32:

• remove experrimental-cert-rotation