Fixes#3951
Bootkube support was removed in Talos 0.9. Talos versions 0.9-0.11
support conversion of self-hosted bootkube-based control plane to the
new style control plane running as static pods managed by Talos.
This commit removes all backwards compatibility and removes conversion
code.
For the k8s controllers, `BootstrapStatus` is removed and a dependency
on `etcd` service status is added (as it was implicitly there via
`BootstrapStatus`).
Remove control plane conversion code.
In k8s upgrade code, remove self-hosted part.
Signed-off-by: Andrey Smirnov <smirnov.andrey@gmail.com>
