Remove `Table.__getstate__` and `Table.__setstate__`
When using distributed training, the code of `os.remove(filename)` may be executed separately by each rank, leading to `FileNotFoundError: [Errno 2] No such file or directory: '/tmp/tmprxxxxxxx.arrow'`

```python
from torch import distributed as dist

if dist.get_rank() == 0:
    dataset = process_dataset(*args, **kwargs)
    objects = [dataset]
else:
    objects = [None]
dist.broadcast_object_list(objects, src=0)
dataset = objects[0]
```
