Multiprocessing in a `filter` or `map` function with a Pytorch model
### Describe the bug

I am trying to use a Pytorch model loaded on CPUs with multiple processes with a `.map` or a `.filter` method.

Usually, when dealing with models that are non-pickable, creating a class such that the `map` function is the method `__call__`, and adding `reduce` helps to solve the problem.

However, here, the command hangs without throwing an error.


### Steps to reproduce the bug

```
from datasets import Dataset
import torch
from torch import nn
from torchvision import models
​
​
class FilterFunction:
    #__slots__ = ("path_model", "model")  # Doesn't change anything uncommented
    def __init__(self, path_model):
        self.path_model = path_model
        model = models.resnet50()
        model.fc = nn.Sequential(
            nn.Linear(2048, 512),
            nn.ReLU(),
            nn.Dropout(0.2),
            nn.Linear(512, 10),
            nn.LogSoftmax(dim=1)
        )
        model.load_state_dict(torch.load(path_model, map_location=torch.device("cpu")))
        model.eval()
        self.model = model
    def __call__(self, batch):
        return [True] * len(batch["id"])
    # Comment this to have an error
    def __reduce__(self):
        return (self.__class__, (self.path_model,))
​
​
dataset = Dataset.from_dict({"id": [0, 1, 2, 4]})
​
# Download (100 MB) at https://github.com/emiliantolo/pytorch_nsfw_model/raw/master/ResNet50_nsfw_model.pth
path_model = "/fsx/hugo/nsfw_image/ResNet50_nsfw_model.pth"
​
filter_function = FilterFunction(path_model=path_model)
​
# Works
filtered_dataset = dataset.filter(filter_function, num_proc=1, batched=True, batch_size=2)
# Doesn't work
filtered_dataset = dataset.filter(filter_function, num_proc=2, batched=True, batch_size=2)
```

### Expected behavior

The command `filtered_dataset = dataset.filter(filter_function, num_proc=2, batched=True, batch_size=2)` should work and not hang.

### Environment info

Datasets: 2.11.0
Pyarrow: 11.0.0
Ubuntu