`test_repl_eio` raises `ResourceWarning`s on Raspbian

[StanFromIreland]

Bug report

Bug description:

This has popped up on two buildbots:

ERROR: test_repl_eio (test.test_pyrepl.test_unix_console.TestUnixConsoleEIOHandling.test_repl_eio)
Warning -- Unraisable exception
ResourceWarning: subprocess 983916 is still running
Warning -- Unraisable exception
ResourceWarning: unclosed file <_io.FileIO name=7 mode='rb' closefd=True>
Warning -- Unraisable exception
ResourceWarning: unclosed file <_io.FileIO name=9 mode='rb' closefd=True>
Re-running test_pyrepl in verbose mode (matching: test_repl_eio)

There have been previous issues with this test, it timed out in the CI (c985822).
Examples, this happens quite frequently:

• ARM64 Raspbian 3.14
• ARM64 Raspbian 3.14 (another case)
• ARM64 Raspbian Debug 3.X
• ARM64 Raspbian Debug 3.14

CPython versions tested on:

CPython main branch, 3.14

Operating systems tested on:

Other

Linked PRs

• gh-139805: Bump test_repl_eio timeout for slow builtbots #139807
• [3.14] gh-139805: Bump test_repl_eio timeout for slow builtbots (GH-139807) #139812
• [3.13] gh-139805: Bump test_repl_eio timeout for slow builtbots (GH-139807) #139813

[cmaloney]

From the ARM64 Raspbian 3.14 one, it looks like the .communicate() is timing out and that means the subprocess / Popen isn't cleaning up the files opened to pass data to the subprocess.

======================================================================
ERROR: test_repl_eio (test.test_pyrepl.test_unix_console.TestUnixConsoleEIOHandling.test_repl_eio)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/stan/buildarea/3.14.stan-raspbian.nondebug/build/Lib/test/test_pyrepl/test_unix_console.py", line 364, in test_repl_eio
    _, err = proc.communicate(timeout=support.SHORT_TIMEOUT)
             ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/stan/buildarea/3.14.stan-raspbian.nondebug/build/Lib/subprocess.py", line 1220, in communicate
    stdout, stderr = self._communicate(input, endtime, timeout)
                     ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/stan/buildarea/3.14.stan-raspbian.nondebug/build/Lib/subprocess.py", line 2127, in _communicate
    self._check_timeout(endtime, orig_timeout, stdout, stderr)
    ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/stan/buildarea/3.14.stan-raspbian.nondebug/build/Lib/subprocess.py", line 1267, in _check_timeout
    raise TimeoutExpired(
    ...<2 lines>...
            stderr=b''.join(stderr_seq) if stderr_seq else None)
subprocess.TimeoutExpired: Command '['/home/stan/buildarea/3.14.stan-raspbian.nondebug/build/python', '-E', '-S', '/home/stan/buildarea/3.14.stan-raspbian.nondebug/build/Lib/test/test_pyrepl/eio_test_script.py']' timed out after 60.0 seconds