Incompatible with iris 3.16

Start with ncdata/dataset_like.py, where the traceback shows the missing set_auto_chartostring attribute, and review the related work in issues #253 and #254. Reproduce the failure with Iris 3.16.0 and confirm the ncdata Iris integration works without the AttributeError.

It looks like ncdata v0.3.2 is not compatible with the latest iris release, v3.16.0 (tested with xarray 2026.7.0).

.pixi/envs/default/lib/python3.14/site-packages/ncdata/iris_xarray.py:54: in cubes_from_xarray
    cubes = to_iris(ncdata, **iris_load_kwargs)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.pixi/envs/default/lib/python3.14/site-packages/ncdata/iris.py:53: in to_iris
    cubes = CubeList(iris.load(dslikes, **iris_load_kwargs))
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.pixi/envs/default/lib/python3.14/site-packages/iris/loading.py:235: in load
    cubes = _load_collection(uris, constraints, callback).combined().cubes()
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.pixi/envs/default/lib/python3.14/site-packages/iris/loading.py:203: in _load_collection
    result = _CubeFilterCollection.from_cubes(cubes, constraints)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.pixi/envs/default/lib/python3.14/site-packages/iris/loading.py:159: in from_cubes
    for c in cubes:
             ^^^^^
.pixi/envs/default/lib/python3.14/site-packages/iris/loading.py:108: in _generate_cubes
    for cube in iris.io.load_data_objects(data_objects, callback):
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.pixi/envs/default/lib/python3.14/site-packages/iris/io/__init__.py:306: in load_data_objects
    yield from load_http(urls, callback)
.pixi/envs/default/lib/python3.14/site-packages/iris/io/__init__.py:286: in load_http
    for cube in handling_format_spec.handler(fnames, callback):
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.pixi/envs/default/lib/python3.14/site-packages/iris/fileformats/netcdf/loader.py:712: in load_cubes
    with CFReader(file_source) as cf:
         ^^^^^^^^^^^^^^^^^^^^^
.pixi/envs/default/lib/python3.14/site-packages/iris/fileformats/cf.py:1356: in __init__
    ds.set_auto_chartostring(False)
    ^^^^^^^^^^^^^^^^^^^^^^^^
.pixi/envs/default/lib/python3.14/site-packages/ncdata/dataset_like.py:74: in __getattr__
    return self.getncattr(attr)
           ^^^^^^^^^^^^^^^^^^^^
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <ncdata.dataset_like.Nc4DatasetLike object at 0x7c1cf981dd30>, attr = 'set_auto_chartostring'

    def getncattr(self, attr: str):
        attrs = self._ncdata.avals
        if attr in attrs:
            result = attrs[attr]
        else:
            # Don't allow it to issue a KeyError, as this upsets 'getattr' usage.
            # Raise an AttributeError instead.
>           raise AttributeError(attr)
E           AttributeError: set_auto_chartostring

.pixi/envs/default/lib/python3.14/site-packages/ncdata/dataset_like.py:59: AttributeError

I noticed you have some work in progress to fix this in #253 and #254