In http://xarray.pydata.org/en/stable/contributing.html#running-the-test-suite

The suggestion is

Using pytest-xdist, one can speed up local testing on multicore machines. To use this feature, you will need to install pytest-xdist via:
pip install pytest-xdist
Then, run pytest with the optional -n argument:
pytest xarray -n 4

pytest-xdist is in the environment (https://github.com/pydata/xarray/blob/main/ci/requirements/environment.yml#L39) no need to reinstall