This is required to upgrade from Talos 0.8.x to 0.9.x. After the cluster
is fully upgraded, control plane is still self-hosted (as it was
bootstrapped with bootkube).
Tool `talosctl convert-k8s` (and library behind it) performs the upgrade
to self-hosted version.
Signed-off-by: Andrey Smirnov <smirnov.andrey@gmail.com>