/sig node
/kind cleanup
/cc @neolit123

As part of the removal of dockershim, we should also remove the deprecated CLI flags that still exist.

The pod-infra-container-image and container-runtime flags are now also deprecated and planned to be removed int v1.27. pod-infra-container-image is being integrated through CRI implementations to avoid needing double specification.

https://github.com/kubernetes/kubernetes/blob/master/pkg/kubelet/config/flags.go#L92-L112