`test_open_websocket_internal_exc` fails intermittently on Darwin

[sarahec]

_______________________ test_open_websocket_internal_exc _______________________

• Exception Group Traceback (most recent call last):
  | File "/nix/store/zcg3dj77vkjmgdn98bxysb4f6anrj9zp-python3.13-trio-0.32.0/lib/python3.13/site-packages/trio/_core/_run.py", line 1125, in aexit
  | raise combined_error_from_nursery
  | ExceptionGroup: Exceptions from Trio nursery (1 sub-exception)
  +-+---------------- 1 ----------------
  | TypeError
  |
  | During handling of the above exception, another exception occurred:
  |
  | Traceback (most recent call last):
  | File "/nix/store/c2k7m9cjkqmdkfgwp2dbdnsvznwvf2jb-python3.13-pytest-trio-0.8.0/lib/python3.13/site-packages/pytest_trio/plugin.py", line 195, in _fixture_manager
  | yield nursery_fixture
  | File "/nix/store/c2k7m9cjkqmdkfgwp2dbdnsvznwvf2jb-python3.13-pytest-trio-0.8.0/lib/python3.13/site-packages/pytest_trio/plugin.py", line 250, in run
  | await self._func(**resolved_kwargs)
  | File "/nix/var/nix/builds/nix-51012-3272202687/source/tests/test_connection.py", line 165, in wrapper
  | return await fn(*args, **kwargs)
  | ^^^^^^^^^^^^^^^^^^^^^^^^^
  | File "/nix/var/nix/builds/nix-51012-3272202687/source/tests/test_connection.py", line 576, in test_open_websocket_internal_exc
  | async with open_websocket(HOST, server.port, RESOURCE, use_ssl=False):
  | ~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  | File "/nix/store/mgd8qy2z9xj5y7lkrfw1zw2l6adanc1d-python3-3.13.12/lib/python3.13/contextlib.py", line 235, in aexit
  | await self.gen.athrow(value)
  | File "/nix/var/nix/builds/nix-51012-3272202687/source/trio_websocket/_impl.py", line 244, in open_websocket
  | _raise(e.exceptions[0])
  | ~~~~~~^^^^^^^^^^^^^^^^^
  | File "/nix/var/nix/builds/nix-51012-3272202687/source/trio_websocket/_impl.py", line 209, in _raise
  | raise exc
  | File "/nix/var/nix/builds/nix-51012-3272202687/source/trio_websocket/_impl.py", line 1562, in _reader_task
  | await handler(event) # type: ignore[operator]
  | ^^^^^^^^^^^^^^^^^^^^
  | File "/nix/var/nix/builds/nix-51012-3272202687/source/tests/test_connection.py", line 566, in raising_ping_event
  | raise internal_error
  | ValueError
  +------------------------------------
  =========================== short test summary info ============================
  FAILED tests/test_connection.py::test_open_websocket_internal_exc - ValueError() [single exception in ExceptionGroup]
  ================= 1 failed, 52 passed, 11 deselected in 2.56s ==================