Image Feature in Datasets Library Fails to Handle bytearray Objects from Spark DataFrames
Hi ! The `Image()` type accepts either
- a `bytes` object containing the image bytes
- a `str` object containing the image path
- a `PIL.Image` object

but it doesn't support `bytearray`, maybe you can convert to `bytes` beforehand ? Hi @lhoestq, 
converting to bytes is certainly possible and would work around the error. However, the core issue is that `Dataset` and `IterableDataset` behave differently with the features.

I’d be happy to work on a fix for this issue. I see, that's an issue indeed. Feel free to ping me if I can help with reviews or any guidance

If it can help, the code that takes a Spark DataFrame and iterates on the rows for `IterableDataset` is here: 

https://github.com/huggingface/datasets/blob/6a96bf313085d7538a999b929a550e14e1d406c9/src/datasets/packaged_modules/spark/spark.py#L49-L53 #self-assign
### Describe the bug

When using `IterableDataset.from_spark()` with a Spark DataFrame containing image data, the `Image` feature class fails to properly process this data type, causing an `AttributeError: 'bytearray' object has no attribute 'get'`

### Steps to reproduce the bug

1. Create a Spark DataFrame with a column containing image data as bytearray objects
2. Define a Feature schema with an Image feature
3. Create an IterableDataset using `IterableDataset.from_spark()`
4. Attempt to iterate through the dataset

```
from pyspark.sql import SparkSession
from datasets import Dataset, IterableDataset, Features, Image, Value

# initialize spark
spark = SparkSession.builder.appName("MinimalRepro").getOrCreate()

# create spark dataframe
data = [(0, open("image.png", "rb").read())]
df = spark.createDataFrame(data, "idx: int, image: binary")

# convert to dataset
features = Features({"idx": Value("int64"), "image": Image()})
ds = Dataset.from_spark(df, features=features)
ds_iter = IterableDataset.from_spark(df, features=features)

# iterate
print(next(iter(ds)))
print(next(iter(ds_iter)))
```

### Expected behavior

The features should work on `IterableDataset` the same way they work on `Dataset`

### Environment info

- `datasets` version: 3.5.0
- Platform: macOS-15.3.2-arm64-arm-64bit
- Python version: 3.12.7
- `huggingface_hub` version: 0.30.2
- PyArrow version: 18.1.0
- Pandas version: 2.2.3
- `fsspec` version: 2024.12.0
