Issue #23277: Remove more unused sys and os imports.

Lib/distutils/tests/test_clean.py

 """Tests for distutils.command.clean."""
-import sys
 import os
 import unittest
 import getpass

Lib/distutils/tests/test_config.py

 """Tests for distutils.pypirc.pypirc."""
-import sys
 import os
 import unittest
 import tempfile

Lib/distutils/tests/test_install_data.py

 """Tests for distutils.command.install_data."""
-import sys
 import os
 import unittest
 import getpass

Lib/distutils/tests/test_install_headers.py

 """Tests for distutils.command.install_headers."""
-import sys
 import os
 import unittest
 import getpass

Lib/distutils/tests/test_unixccompiler.py

 """Tests for distutils.unixccompiler."""
-import os
 import sys
 import unittest
 from test.support import EnvironmentVarGuard, run_unittest

Lib/lib2to3/tests/test_parser.py

@@ -15,7 +15,6 @@ from test.support import verbose
 
 # Python imports
 import os
-import sys
 import unittest
 import warnings
 import subprocess

Lib/lib2to3/tests/test_pytree.py

@@ -11,7 +11,6 @@ especially when debugging a test.
 
 from __future__ import with_statement
 
-import sys
 import warnings
 
 # Testing imports

Lib/lib2to3/tests/test_util.py

@@ -3,9 +3,6 @@
 # Testing imports
 from . import support
 
-# Python imports
-import os.path
-
 # Local imports
 from lib2to3.pytree import Node, Leaf
 from lib2to3 import fixer_util

Lib/test/seq_tests.py

@@ -318,7 +318,6 @@ class CommonTest(unittest.TestCase):
             self.assertEqual(id(s), id(s*1))
 
     def test_bigrepeat(self):
-        import sys
         if sys.maxsize <= 2147483647:
             x = self.type2test([0])
             x *= 2**16

Lib/test/test_importlib/source/test_source_encoding.py

@@ -5,7 +5,6 @@ machinery = util.import_importlib('importlib.machinery')
 import codecs
 import importlib.util
 import re
-import sys
 import types
 # Because sys.path gets essentially blanked, need to have unicodedata already
 # imported for the parser to use.

Lib/test/test_itertools.py

@@ -4,7 +4,6 @@ from itertools import *
 import weakref
 from decimal import Decimal
 from fractions import Fraction
-import sys
 import operator
 import random
 import copy

Lib/test/test_set.py

@@ -6,7 +6,6 @@ import operator
 import copy
 import pickle
 from random import randrange, shuffle
-import sys
 import warnings
 import collections
 import collections.abc

Lib/test/test_xmlrpc.py

@@ -9,7 +9,6 @@ import xmlrpc.server
 import http.client
 import http, http.server
 import socket
-import os
 import re
 import io
 import contextlib