[test-upstream] import cleanup fixture from distributed (#6650)

Co-authored-by: keewis <keewis@users.noreply.github.com>

Author: andersy005

xarray/tests/test_distributed.py

@@ -12,7 +12,7 @@
 
 from dask.distributed import Client, Lock
 from distributed.client import futures_of
-from distributed.utils_test import cluster, gen_cluster, loop
+from distributed.utils_test import cluster, gen_cluster, loop, cleanup  # noqa: F401
 
 import xarray as xr
 from xarray.backends.locks import HDF5_LOCK, CombinedLock