Merge pull request #5574 from kannon92/move-cgroup-v1-unsupported

[KEP-5573]: Remove cgroup v1 support

Author: k8s-ci-robot

keps/prod-readiness/sig-node/5573.yaml

@@ -0,0 +1,6 @@
+# The KEP must have an approver from the
+# "prod-readiness-approvers" group
+# of http://git.k8s.io/enhancements/OWNERS_ALIASES
+kep-number: 5573
+beta:
+  approver: "@deads2k"