bpo-39481: PEP 585 for a variety of modules (GH-19423)

- concurrent.futures
- ctypes
- http.cookies
- multiprocessing
- queue
- tempfile
- unittest.case
- urllib.parse
diff --git a/Lib/concurrent/futures/thread.py b/Lib/concurrent/futures/thread.py
index 2aa4e17..2810b35 100644
--- a/Lib/concurrent/futures/thread.py
+++ b/Lib/concurrent/futures/thread.py
@@ -10,6 +10,7 @@
 import itertools
 import queue
 import threading
+import types
 import weakref
 import os
 
@@ -57,6 +58,8 @@
         else:
             self.future.set_result(result)
 
+    __class_getitem__ = classmethod(types.GenericAlias)
+
 
 def _worker(executor_reference, work_queue, initializer, initargs):
     if initializer is not None: