Run pyupgrade for python 3.7 & 3.8. (#16110)

tests/server.py

@@ -26,6 +26,7 @@ from typing import (
     Any,
     Awaitable,
     Callable,
+    Deque,
     Dict,
     Iterable,
     List,
@@ -41,7 +42,7 @@ from typing import (
 from unittest.mock import Mock
 
 import attr
-from typing_extensions import Deque, ParamSpec
+from typing_extensions import ParamSpec
 from zope.interface import implementer
 
 from twisted.internet import address, threads, udp