Drop three unused imports (#141875)

Lib/_pyrepl/simple_interact.py

@@ -31,7 +31,6 @@
 import sys
 import code
 import warnings
-import errno
 
 from .readline import _get_reader, multiline_input, append_history_file
 

Lib/asyncio/tools.py

@@ -1,6 +1,6 @@
 """Tools to analyze tasks running in asyncio programs."""
 
-from collections import defaultdict, namedtuple
+from collections import defaultdict
 from itertools import count
 from enum import Enum
 import sys

Lib/shelve.py

@@ -57,7 +57,6 @@
 """
 
 from pickle import DEFAULT_PROTOCOL, dumps, loads
-from io import BytesIO
 
 import collections.abc