transformers.image_transforms.normalize wrong types
Author: CalOmnie
Pull request: yes

# What does this PR do?

`transformers.image_transforms.normalize` types `std` and `mean` as Iterable, and checks for that, but calls `len` on them. The proper type for a sized iterable is `Sequence`, this PR adds that.

Fixes #35772


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Comments:
This PR was probably supposed to be a refactor, and should not change the execution paths of the code. However, it turns out that numpy arrays are Iterables but not Sequences, and therefore the execution paths changed. Client code that used to pass numpy arrays for `mean` and `std` fails now. We found this because it broke our MiniCPM video-chat pipeline. Case here: https://huggingface.co/openbmb/MiniCPM-V-2_6/discussions/53

```python
from typing import Iterable, Sequence
import numpy as np

x = np.ones(3)
print(isinstance(x, Iterable))
#> True
print(isinstance(x, Sequence))
#> False
```

I can see that the type hint does not include numpy arrays, but passing a numpy array (which I guess is the intention of the type hint `Sequence[float]`  /  `Iterable[float]`) is reasonable, too. Would you say that client code is responsible for adjusting? Or could we revert? Or what would guys you suggest? 

Best :)

Edit: I found that some client libs like vLLM are adjusting accordingly https://github.com/vllm-project/vllm/pull/12781/commits/e8616d7826d7646609ef409a01f8e2a2ff559e14

Oh, you're right, I went one level too high in the typing, the type needed was `Collection` not `Sequence`, see [here](https://docs.python.org/3/library/collections.abc.html#collections.abc.Container)

![image](https://github.com/user-attachments/assets/22724ac2-f749-4a06-a606-3cc4b847a6b0)

I will have a PR out tonight unless someone beats me to it.

```
>>> from typing import Collection
>>> import numpy as np
>>> a = np.ones(10)
>>> isinstance(a, Collection)
True
```


Alright I created a fix and modified some tests to make sure it worked [here](https://github.com/huggingface/transformers/pull/36301)