bpo-35202: Remove unused imports in idlelib (GH-10438)

Lib/idlelib/idle_test/test_config.py

@@ -4,7 +4,6 @@
 Much of IdleConf is also exercised by ConfigDialog and test_configdialog.
 """
 from idlelib import config
-import copy
 import sys
 import os
 import tempfile

Lib/idlelib/idle_test/test_config_key.py

@@ -2,7 +2,6 @@
 
 from idlelib import config_key
 from test.support import requires
-import sys
 import unittest
 from tkinter import Tk
 from idlelib.idle_test.mock_idle import Func

Lib/idlelib/idle_test/test_rpc.py

@@ -3,7 +3,6 @@
 from idlelib import rpc
 import unittest
 
-import marshal
 
 
 class CodePicklerTest(unittest.TestCase):