This option makes pyboard.py exit as soon as the script/command is
successfully sent to the device, ie it does not wait for any output. This
can help to avoid hangs if the board is being rebooted with --comman (for
example).
Example usage:
$ python3 ./tools/pyboard.py --device /dev/ttyUSB0 --no-follow \
--command 'import machine; machine.reset()'