remove unused imports (closes #12432)

A patch from Vincent Legoll.

Lib/binhex.py

@@ -23,7 +23,6 @@ hexbin(inputfilename, outputfilename)
 #
 import io
 import os
-import sys
 import struct
 import binascii
 

Lib/cgitb.py

@@ -31,7 +31,6 @@ import tempfile
 import time
 import tokenize
 import traceback
-import types
 
 def reset():
     """Return a string that resets the CGI and browser to a known state."""

Lib/contextlib.py

@@ -2,7 +2,6 @@
 
 import sys
 from functools import wraps
-from warnings import warn
 
 __all__ = ["contextmanager", "closing", "ContextDecorator"]
 

Lib/glob.py

@@ -1,5 +1,6 @@
 """Filename globbing utility."""
 
+import sys
 import os
 import re
 import fnmatch

Lib/inspect.py

@@ -33,7 +33,6 @@ import sys
 import os
 import types
 import itertools
-import string
 import re
 import imp
 import tokenize

Lib/textwrap.py

@@ -7,7 +7,7 @@
 
 __revision__ = "$Id$"
 
-import string, re
+import re
 
 __all__ = ['TextWrapper', 'wrap', 'fill', 'dedent']
 

Lib/turtle.py

@@ -108,7 +108,6 @@ import tkinter as TK
 import types
 import math
 import time
-import os
 import inspect
 
 from os.path import isfile, split, join