this process is a fork process by default on linux

but these processes *must* be fork processes because we
can't re-import the unknown user workflow script again.

so make that more explicit.

(longer term, forked processes need to go away throughout
Parsl - see PR #2343, but this PR is not for that)

parsl/monitoring/monitoring.py

@@ -5,7 +5,7 @@
 import os
 import queue
 import time
-from multiprocessing import Event, Process
+from multiprocessing import Event
 from multiprocessing.queues import Queue
 from typing import TYPE_CHECKING, Literal, Optional, Tuple, Union, cast
 
@@ -164,11 +164,11 @@ def start(self, dfk_run_dir: str, config_run_dir: Union[str, os.PathLike]) -> No
         self.dbm_proc.start()
         logger.info("Started the router process {} and DBM process {}".format(self.router_proc.pid, self.dbm_proc.pid))
 
-        self.filesystem_proc = Process(target=filesystem_receiver,
-                                       args=(self.resource_msgs, dfk_run_dir),
-                                       name="Monitoring-Filesystem-Process",
-                                       daemon=True
-                                       )
+        self.filesystem_proc = ForkProcess(target=filesystem_receiver,
+                                           args=(self.resource_msgs, dfk_run_dir),
+                                           name="Monitoring-Filesystem-Process",
+                                           daemon=True
+                                           )
         self.filesystem_proc.start()
         logger.info(f"Started filesystem radio receiver process {self.filesystem_proc.pid}")