[Tracking Issue] `kind/design` to `kind/feature` migration cleanup

[MadhavJivrajani]

Following up from the communication that was sent out regarding the migration of kind/design to kind/feature and the changes that would entail - this issue is for tracking the cleanup work that needs to be done for completing that migration.

The next step is to actually remove the label from the GitHub repos that did not opt-in for the kind/design label (see the above linked communication for more details), removing the label from the repo entails two main things:

• First, remove kind/design from all open issues and PRs in said repo
• Second, after no open issue/PR has this label anymore, remove it from the repository itself.

Currently, the following issues have the kind/design on open issues/PRs:

• kubernetes: 26 (note that kubeadm is an opt-in repo) (26 open are all kubeadm)
• kubernets-sigs: 27 (note that k-sigs/cluster-api and `k-sigs/controller-runtime are opt-in repos)
• kubernetes-client: 0
• kubernetes-csi: 0
• kubernetes-security: 0

/sig contributor-experience
/area github-management
/assign @nikhita