Don't shield proc waits

tractor/_spawn.py

@@ -273,9 +273,13 @@ async def new_proc(
                 # ``trio.Process.__aexit__()`` (it tears down stdio
                 # which will kill any waiting remote pdb trace).
 
+                # TODO: No idea how we can enforce zombie
+                # reaping more stringently without the shield
+                # we used to have below...
+
                 # always "hard" join sub procs:
                 # no actor zombies allowed
-                with trio.CancelScope(shield=True):
+                # with trio.CancelScope(shield=True):
                 await proc.wait()
         else:
             # `multiprocessing`