Bugfix ignore function when creating new_fingerprint for caching
Adding "function" to the kwargs to ignore when computing the fingerprint will break `map` caching. Indeed passing two different function would result in two different datasets that have the same fingerprint - and the cache wouldn't be able to distinguish them.

E.g this code would reload ds1 from the cache insetad of computing the dataset for ds2
```python
ds = Dataset.from_dict({"a": [1, 2, 3]})
ds1 = ds.map(lambda x: {"b": 1})
ds2 = ds.map(lambda x: {"b": 2})
```
maybe fixes: #5109