Replace hardcoded 5 seconds with support.SHORT_TIMEOUT.
Fix the following error on slow CI such as GitHub Action UBSan:
test test_pyrepl failed -- Traceback (most recent call last):
File "Lib/test/test_pyrepl/test_unix_console.py", line 362, in test_repl_eio
_, err = proc.communicate(timeout=5) # sleep for pty to settle
~~~~~~~~~~~~~~~~^^^^^^^^^^^
File "Lib/subprocess.py", line 1219, in communicate
stdout, stderr = self._communicate(input, endtime, timeout)
~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^
File "Lib/subprocess.py", line 2126, in _communicate
self._check_timeout(endtime, orig_timeout, stdout, stderr)
~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "Lib/subprocess.py", line 1266, in _check_timeout
raise TimeoutExpired(
...<2 lines>...
stderr=b''.join(stderr_seq) if stderr_seq else None)
subprocess.TimeoutExpired: Command '[...]' timed out after 5 seconds