Fix fixture 'loop_in_thread' not found error in tests

[lgarrison]

While running pytest on dask_mpi, I encountered the below fixture 'loop_in_thread' not found error. A quick search brought up dask/dask#9337, where they encountered the same error and fixed it with the extra imports that are in this PR. I think this is a workaround rather than a long-term fix, but it will unstick the CI while the issue is addressed upstream.

(venv8) lgarrison@scclin021:~/scc/repo/dask-mpi$ pytest -xv dask_mpi/
================================================= test session starts ==================================================
platform linux -- Python 3.8.12, pytest-7.1.3, pluggy-1.0.0 -- /mnt/home/lgarrison/scc/daskdistrib/venv8/bin/python
cachedir: .pytest_cache
hypothesis profile 'default' -> database=DirectoryBasedExampleDatabase('/mnt/home/lgarrison/scc/repo/dask-mpi/.hypothesis/examples')
rootdir: /mnt/home/lgarrison/scc/repo/dask-mpi, configfile: setup.cfg
plugins: anyio-3.5.0, hypothesis-6.23.1
collected 12 items                                                                                                     

dask_mpi/tests/test_cli.py::test_basic[distributed.Worker] ERROR                                                 [  8%]

======================================================== ERRORS ========================================================
___________________________________ ERROR at setup of test_basic[distributed.Worker] ___________________________________
file /mnt/home/lgarrison/scc/repo/dask-mpi/dask_mpi/tests/test_cli.py, line 23
  @pytest.mark.parametrize(
      "worker_class",
      ["distributed.Worker", "distributed.Nanny", "dask_cuda.CUDAWorker"],
  )
  def test_basic(loop, worker_class, mpirun):
file /mnt/home/lgarrison/scc/daskdistrib/venv8/lib/python3.8/site-packages/distributed/utils_test.py, line 126
  @pytest.fixture
  def loop(loop_in_thread):
E       fixture 'loop_in_thread' not found
>       available fixtures: allow_run_as_root, anyio_backend, anyio_backend_name, anyio_backend_options, cache, capfd, capfdbinary, caplog, capsys, capsysbinary, doctest_namespace, loop, monkeypatch, mpirun, pytestconfig, record_property, record_testsuite_property, record_xml_attribute, recwarn, tmp_path, tmp_path_factory, tmpdir, tmpdir_factory
>       use 'pytest --fixtures [testpath]' for help on them.

/mnt/home/lgarrison/scc/daskdistrib/venv8/lib/python3.8/site-packages/distributed/utils_test.py:126
=================================================== warnings summary ===================================================
dask_mpi/tests/test_cli.py:14
  /mnt/home/lgarrison/scc/repo/dask-mpi/dask_mpi/tests/test_cli.py:14: FutureWarning: tmpfile is deprecated and will be removed in a future release. Please use dask.utils.tmpfile instead.
    from distributed.utils import import_term, tmpfile

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
================================================= slowest 10 durations =================================================
0.00s setup    dask_mpi/tests/test_cli.py::test_basic[distributed.Worker]
0.00s teardown dask_mpi/tests/test_cli.py::test_basic[distributed.Worker]
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! stopping after 1 failures !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
============================================= 1 warning, 1 error in 0.59s ==============================================

[lgarrison]

Not sure I understand the pre-commi.ci failure, it looks like it found issues, then fixed them, right? Do I need to do something else for it to pass the check?

[jacobtomlinson]

This looks great, thanks for this.

It looks like black and isort are fighting, one is modifying the files and the other is reverting which is why the automated commit didn't fix the failure.

I've pushed some extra config to get them to play nice.

[kmpaul]

Thanks, Jacob!