gh-151428: Remove unused imports in the stdlib (GH-151440)

(cherry picked from commit a7885b4)

Co-authored-by: Ivy Xu <fakeshadow1337@gmail.com>

Author: ByteFlowing1337

Lib/asyncio/coroutines.py

@@ -1,7 +1,6 @@
 __all__ = 'iscoroutinefunction', 'iscoroutine'
 
 import collections.abc
-import inspect
 import os
 import sys
 import types

Lib/unittest/mock.py

@@ -24,7 +24,6 @@
 )
 
 
-import asyncio
 import contextlib
 import io
 import inspect

Lib/zipfile/__init__.py

@@ -4,7 +4,6 @@
 XXX references to utf-8 need further investigation.
 """
 import binascii
-import importlib.util
 import io
 import os
 import shutil