Merge pull request pydata#2 from rabernat/ryan/fix/zarr-v3-2

Fix test_roundtrip_empty_vlen_string_array

Author: TomAugspurger

xarray/tests/test_backends.py

@@ -927,7 +927,8 @@ def test_roundtrip_empty_vlen_string_array(self) -> None:
                 if actual["a"].dtype.metadata is not None:
                     assert check_vlen_dtype(actual["a"].dtype) is str
             else:
-                assert actual["a"].dtype == np.dtype("=U1")
+                # zarr v3 sends back "<U1"
+                assert np.issubdtype(actual["a"].dtype, np.dtype("=U1"))
 
     @pytest.mark.parametrize(
         "decoded_fn, encoded_fn",