Use sys.stdlib_module_names where available

Use the new sys.stdlib_module_names when and where avaialble.

Fix up test cases to remove Python 2 modules

---------

Co-authored-by: Ian Stapleton Cordasco <graffatcolmingov@gmail.com>

Author: Dreamsorcerer

flake8_import_order/__init__.py

@@ -1,7 +1,13 @@
 import ast
+import sys
 from collections import namedtuple
 from enum import IntEnum
 
+if sys.version_info >= (3, 10):
+    STDLIB_NAMES = sys.stdlib_module_names | {"__main__", "test"}
+else:
+    from .stdlib_list import STDLIB_NAMES
+
 from .__about__ import __author__
 from .__about__ import __copyright__
 from .__about__ import __email__
@@ -10,7 +16,6 @@
 from .__about__ import __title__
 from .__about__ import __uri__
 from .__about__ import __version__
-from .stdlib_list import STDLIB_NAMES
 
 __all__ = [
     "__title__",

tests/test_cases/complete_appnexus.py

@@ -4,7 +4,6 @@
 from functools import *
 import os
 from os import path
-import StringIO
 import sys
 
 import X

tests/test_cases/complete_edited.py

@@ -2,7 +2,6 @@
 
 import ast
 import os
-import StringIO
 import sys
 from functools import *
 from os import path

tests/test_cases/complete_google.py

@@ -4,7 +4,6 @@
 from functools import *
 import os
 from os import path
-import StringIO
 import sys
 
 import localpackage

tests/test_cases/complete_pycharm.py

@@ -1,6 +1,5 @@
 # pycharm
 
-import StringIO
 import ast
 import os
 import sys

tests/test_cases/complete_smarkets.py

@@ -2,7 +2,6 @@
 
 import ast
 import os
-import StringIO
 import sys
 from functools import *
 from os import path