Issue #22043: time.monotonic() is now always available

threading.Lock.acquire(), threading.RLock.acquire() and socket operations now
use a monotonic clock, instead of the system clock, when a timeout is used.
diff --git a/Lib/subprocess.py b/Lib/subprocess.py
index 6dfa40b..bb7d0dc 100644
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -365,10 +365,7 @@
 import builtins
 import warnings
 import errno
-try:
-    from time import monotonic as _time
-except ImportError:
-    from time import time as _time
+from time import monotonic as _time
 
 # Exception classes used by this module.
 class SubprocessError(Exception): pass