UPSTREAM: <drop>: add missing import restrictions

when we run verify-import-boss.sh it fails with the following error

errors in package "k8s.io/kubernetes/cmd/kubeadm/app/phases/bootstraptoken/node":
the following imports did not match any allowed prefix:
  gopkg.in/yaml.v3
  k8s.io/kube-openapi/pkg/validation/spec

note: this should be an upstream fix, not sure why we don't see this
error in upstream, does upstream not run this job in verify?
investigate and take proper action for this commit

cmd/kubeadm/.import-restrictions

@@ -8,6 +8,7 @@ rules:
       - k8s.io/kube-openapi/pkg/schemaconv
       - k8s.io/kube-openapi/pkg/handler3
       - k8s.io/kube-openapi/pkg/spec3
+      - k8s.io/kube-openapi/pkg/validation/spec
   - selectorRegexp: k8s[.]io/kube-proxy/
     allowedPrefixes:
       - k8s.io/kube-proxy/config/v1alpha1
@@ -19,3 +20,4 @@ rules:
       - gopkg.in/inf.v0
       - gopkg.in/square/go-jose.v2
       - gopkg.in/yaml.v2
+      - gopkg.in/yaml.v3