kubelet[20592]: Flag --cgroup-driver has been deprecated, This parameter should be set via the config file specified by the Kubelet's --config

Note:

Since --cgroup-driver flag has been deprecated by kubelet,
if you have that in /var/lib/kubelet/kubeadm-flags.env or /etc/default/kubelet(/etc/sysconfig/kubelet for RPMs),

please remove it and use the KubeletConfiguration instead (stored in /var/lib/kubelet/config.yaml by default).