Make the setup phase of the test a bit more consistent - wait for the
machine to be ready, connection refused to be cleared (after reboots).
This doesn't change anything in the tests themselves, but hopefully
should reduce number of flakes like: https://github.com/siderolabs/talos/actions/runs/15895820994/job/44827039818
Signed-off-by: Andrey Smirnov <andrey.smirnov@siderolabs.com>