tests: unconditionalize some imports

Now that we require Python 3 we can simplify these imports.

Differential Revision: https://phab.mercurial-scm.org/D12245

tests/run-tests.py

@@ -57,8 +57,10 b' import json'
 import multiprocessing
 import os
 import platform
+import queue
 import random
 import re
+import shlex
 import shutil
 import signal
 import socket
@@ -73,20 +75,7 b' import uuid'
 import xml.dom.minidom as minidom
 
 WINDOWS = os.name == r'nt'
-
-try:
-    import Queue as queue
-except ImportError:
-    import queue
-
-try:
-    import shlex
-
-    shellquote = shlex.quote
-except (ImportError, AttributeError):
-    import pipes
-
-    shellquote = pipes.quote
+shellquote = shlex.quote
 
 
 processlock = threading.Lock()