Couldn't cast array of type fixed_size_list to Sequence(Value(float64))
### Describe the bug

I have a dataset with an embedding column, when I try to map that dataset I get the following exception:

```
Traceback (most recent call last):
  File "/Users/jmif/.virtualenvs/llm-training/lib/python3.10/site-packages/datasets/arrow_dataset.py", line 3189, in map
    for rank, done, content in iflatmap_unordered(
  File "/Users/jmif/.virtualenvs/llm-training/lib/python3.10/site-packages/datasets/utils/py_utils.py", line 1387, in iflatmap_unordered
    [async_result.get(timeout=0.05) for async_result in async_results]
  File "/Users/jmif/.virtualenvs/llm-training/lib/python3.10/site-packages/datasets/utils/py_utils.py", line 1387, in <listcomp>
    [async_result.get(timeout=0.05) for async_result in async_results]
  File "/Users/jmif/.virtualenvs/llm-training/lib/python3.10/site-packages/multiprocess/pool.py", line 774, in get
    raise self._value
TypeError: Couldn't cast array of type
fixed_size_list<item: float>[2]
to
Sequence(feature=Value(dtype='float32', id=None), length=2, id=None)
```

### Steps to reproduce the bug

Here's a simple repro script:

```
from datasets import Features, Value, Sequence, ClassLabel, Dataset

dataset_features = Features({
    'text': Value('string'),
    'embedding': Sequence(Value('double'), length=2),
    'categories': Sequence(ClassLabel(names=sorted([
        'one',
        'two',
        'three'
    ]))),
})

dataset = Dataset.from_dict(
    {
        'text': ['A'] * 10000,
        'embedding': [[0.0, 0.1]] * 10000,
        'categories': [[0]] * 10000,
    },
    features=dataset_features
)

def test_mapper(r):
    r['text'] = list(map(lambda t: t + ' b', r['text']))
    return r


dataset = dataset.map(test_mapper, batched=True, batch_size=10, features=dataset_features, num_proc=2)
```

Removing the embedding column fixes the issue!

### Expected behavior

The mapping completes successfully.

### Environment info

- `datasets` version: 2.14.4
- Platform: macOS-14.0-arm64-arm-64bit
- Python version: 3.10.12
- Huggingface_hub version: 0.17.1
- PyArrow version: 13.0.0
- Pandas version: 2.0.3