Silence error in test_zarr_region_chunk_partial_offset on Windows (#10793)

* Silence error on Windows

* allow failures for any version of windows

Author: shoyer

xarray/tests/test_backends.py

@@ -7520,6 +7520,10 @@ def test_zarr_append_chunk_partial(self):
                     mode="a",
                 )
 
+    @pytest.mark.xfail(
+        ON_WINDOWS,
+        reason="Permission errors from Zarr: https://github.com/pydata/xarray/pull/10793",
+    )
     @requires_dask
     def test_zarr_region_chunk_partial_offset(self):
         # https://github.com/pydata/xarray/pull/8459#issuecomment-1819417545