Update Lib/test/test_tkinter/test_tkinter_pipe.py

If the test fails, let it fail quickly.

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

Author: mdehoon

Lib/test/test_tkinter/test_tkinter_pipe.py

@@ -46,7 +46,7 @@ def test_tkinter_pipe_unbuffered(self):
 
         proc.stdin.write(b"print('goodbye')\n")
         proc.stdin.write(b"quit()\n")
-        stdout, stderr = proc.communicate()
+        stdout, stderr = proc.communicate(timeout=support.SHORT_TIMEOUT)
         stdout = stdout.decode()
         self.assertEqual(stdout.strip(), 'goodbye')