Add back in the aexit hook but start the server as an orphaned proces…

…s instead so python releases everything before the server tries to lock it (#14010)

hardware-testing/hardware_testing/opentrons_api/helpers_ot3.py

@@ -4,10 +4,10 @@
 from datetime import datetime
 from enum import Enum
 from math import pi
-from subprocess import run
+from subprocess import run, Popen
 from time import time
 from typing import Callable, Coroutine, Dict, List, Optional, Tuple, Union
-
+import atexit
 from opentrons_hardware.drivers.can_bus import DriverSettings, build, CanMessenger
 from opentrons_hardware.drivers.can_bus import settings as can_bus_settings
 from opentrons_hardware.firmware_bindings.constants import SensorId
@@ -77,6 +77,15 @@ def stop_server_ot3() -> None:
  """Stop opentrons-robot-server on the OT3."""
  print('Stopping "opentrons-robot-server"...')
  run(["systemctl", "stop", "opentrons-robot-server"])
+ atexit.register(restart_server_ot3)
+
+
+def restart_server_ot3() -> None:
+ """Start opentrons-robot-server on the OT3."""
+ print('Starting "opentrons-robot-server"...')
+ Popen(
+ ["systemctl", "restart", "opentrons-robot-server", "&"],
+ )
 
 
 def start_server_ot3() -> None: