Deprecate kubernetes-cni deb/rpm packages

[justaugustus]

Capturing this discussion thread: https://groups.google.com/d/topic/kubernetes-sig-release/yhf7hAqJEN0/discussion
I'll expand on the description once we come to consensus on approach on the mailing list.

First phase of this is here: #884

• Bundle CNI plugins in the kubelet:
  • kubepkg: kubepkg: Bundle CNI plugins (v0.8.6) in kubelet deb/rpm packages #1330
  • build-admin branch fix: Bundle CNI plugins (v0.8.6) in kubelet deb/rpm packages #1309

/priority important-soon
/milestone v1.17
/area release-eng
/sig release
/kind cleanup documentation

[justaugustus]

/assign
cc: @kubernetes/release-engineering @kubernetes/sig-release-admins

[justaugustus]

I've still got a bit to do on refactoring our deb/rpm tooling, so this is slipping to 1.18.

/milestone v1.18

[justaugustus]

Tracking issue for kubepkg, our new tool for building debs (and eventually rpms): #1027
Once we start committing static build definitions/specs to k/release by Kubernetes version, we'll be able to fold the CNI plugins into the kubelet package.

Work on this is already in progress for 1.18...