Previously Talos would not shutdown gracefully if hyper-v issued the
'perform_shutdown' call. Said call would execute '/sbin/poweroff' which
did not exist in Talos. We hardlink machined to '/sbin/poweroff' and
make it send a shutdown API call to PID 1 machined.
Fixes#5641
Signed-off-by: Philipp Sauter <philipp.sauter@siderolabs.com>
