pyarrow.lib.ArrowTypeError: Expected dict key of type str or bytes, got 'int'
### Describe the bug

A dict with its keys are all str but get following error
```python
test_data=[{'input_ids':[1,2,3],'labels':[[Counter({2:1})]]}]
dataset = datasets.Dataset.from_list(test_data)
```
```bash
pyarrow.lib.ArrowTypeError: Expected dict key of type str or bytes, got 'int'
```

### Steps to reproduce the bug

.

### Expected behavior

.

### Environment info

datasets 3.3.2