Mac: Bad file descriptor

Not sure why this has suddenly changed, but tests are now erroring on Mac OSX runners. Worst part is that the process doesn't end after this error, so the CI doesn't fail until it timeouts after 15 minutes.

See test results here (I've also verified on a separate PR, so it's not related to the coverage version bump):
https://github.com/aio-libs/aiohttp-devtools/actions/runs/3783707241/jobs/6439936092

INTERNALERROR> Traceback (most recent call last):
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/_pytest/main.py", line 269, in wrap_session
INTERNALERROR>     session.exitstatus = doit(config, session) or 0
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/_pytest/main.py", line 323, in _main
INTERNALERROR>     config.hook.pytest_runtestloop(session=session)
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/pluggy/_hooks.py", line 265, in __call__
INTERNALERROR>     return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult)
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/pluggy/_manager.py", line 80, in _hookexec
INTERNALERROR>     return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/pluggy/_callers.py", line 60, in _multicall
INTERNALERROR>     return outcome.get_result()
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/pluggy/_result.py", line 60, in get_result
INTERNALERROR>     raise ex[1].with_traceback(ex[2])
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/pluggy/_callers.py", line 39, in _multicall
INTERNALERROR>     res = hook_impl.function(*args)
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/_pytest/main.py", line 348, in pytest_runtestloop
INTERNALERROR>     item.config.hook.pytest_runtest_protocol(item=item, nextitem=nextitem)
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/pluggy/_hooks.py", line 265, in __call__
INTERNALERROR>     return self._hookexec(self.name, self.get_hookimpls(), kwargs, firstresult)
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/pluggy/_manager.py", line 80, in _hookexec
INTERNALERROR>     return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/pluggy/_callers.py", line 60, in _multicall
INTERNALERROR>     return outcome.get_result()
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/pluggy/_result.py", line 60, in get_result
INTERNALERROR>     raise ex[1].with_traceback(ex[2])
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/pluggy/_callers.py", line 39, in _multicall
INTERNALERROR>     res = hook_impl.function(*args)
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/pytest_forked/__init__.py", line 51, in pytest_runtest_protocol
INTERNALERROR>     reports = forked_run_report(item)
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/pytest_forked/__init__.py", line 73, in forked_run_report
INTERNALERROR>     ff = py.process.ForkedFunc(runforked)
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/py/_process/forkedfunc.py", line 50, in __init__
INTERNALERROR>     self._child(nice_level, child_on_start, child_on_exit)
INTERNALERROR>   File "/Users/runner/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/py/_process/forkedfunc.py", line 74, in _child
INTERNALERROR>     stdout.close()
INTERNALERROR> OSError: [Errno 9] Bad file descriptor

Start by reproducing the failure on a Mac OSX runner using the linked GitHub Actions results. Trace the pytest_forked path through pytest_forked/init.py and the reported py/_process/forkedfunc.py stdout.close() call. Done means the tests no longer raise the bad-file-descriptor error and the process exits instead of waiting for the CI timeout.