Automatic merge from submit-queue (batch tested with PRs 56995, 58498, 57426, 58902, 58863). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
kubelet: remove the rktshim directory
This package contains only placeholders without actual implementation.
Since it is not currently under active development, remove it to avoid
unnecessary change needed whenever the interface is changed.