prune .import-restrictions

specifically:

- cmd/kubeadm/.import-restrictions
  - we don't need to explicitly allow k8s.io repos (external or published)
- rm pkg/controller/.import-restrictions
  - pkg/client/unversioned was removed in 59042
- pkg/kubectl/.import-restrictions
  - pkg/printers is no longer used
  - pkg/api was masking all of the pkg/apis prefixes
- rm staging/src/k8s.io/code-generator/cmd/lister-gen/.import-restrictions
  - noop / empty file
- test/e2e/framework/.import-restrictions
  - we don't need to explicitly allow k8s.io repos (external or published)

cmd/kubeadm/.import-restrictions

@@ -1,10 +1,4 @@
 rules:
-  - selectorRegexp: k8s[.]io/(api/|apimachinery/|apiextensions-apiserver/|apiserver/)
-    allowedPrefixes:
-      - ''
-  - selectorRegexp: k8s[.]io/client-go/
-    allowedPrefixes:
-      - ''
   - selectorRegexp: k8s[.]io/kubelet/
     allowedPrefixes:
       - k8s.io/kubelet/config/v1beta1