Fixed convert_batch_to_list_format staticmethod function call
Author: Sai-Suraj-27
Pull request: yes

# What does this PR do?
Fixes these [failing tests](https://github.com/huggingface/transformers/actions/runs/19758977591/job/56616632584#step:14:5132)

<img width="1306" height="207" alt="image" src="https://github.com/user-attachments/assets/c90a23e0-5b1a-4207-869a-1207b10de8a7" />

## Before submitting
- [ ] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
- [x] Did you read the [contributor guideline](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md#create-a-pull-request),
      Pull Request section?
- [ ] Was this discussed/approved via a Github issue or the [forum](https://discuss.huggingface.co/)? Please add a link
      to it if that's the case.
- [ ] Did you make sure to update the documentation with your changes? Here are the
      [documentation guidelines](https://github.com/huggingface/transformers/tree/main/docs), and
      [here are tips on formatting docstrings](https://github.com/huggingface/transformers/tree/main/docs#writing-source-documentation).
- [ ] Did you write any new necessary tests?


## Who can review?
@ArthurZucker @zucchini-nlp @itazap 

Comments:
Hi @Sai-Suraj-27, these tests are passing locally for me. Can you pull the latest version from `main` and check the bug is still there?

> Hi @Sai-Suraj-27, these tests are passing locally for me. Can you pull the latest version from `main` and check the bug is still there?

Hey, @Rocketknight1. Thaks for the review. They were actually passing for me as well locally when i first tried, but they are passing locally because of this special else condition which will be used to run the test case by removing the 1st `self` parameter only when we run the test locally. So, it is failing in the actual CI, but passing locally.

https://github.com/huggingface/transformers/blob/297f5ae8aba5d933c07745ece28ce0e4a6e44ec0/src/transformers/testing_utils.py#L651-L656


Okay this problem goes deeper than i realized lmao, but thank you for surfacing that one!

`"staticmethod" in inspect.getsource(test_case).strip()` is extremely hacky, and we definitely don't want to do that. I'll see if I can figure out a better solution.

> Okay this problem goes deeper than i realized lmao, but thank you for surfacing that one!
> 
> `"staticmethod" in inspect.getsource(test_case).strip()` is extremely hacky, and we definitely don't want to do that. I'll see if I can figure out a better solution.

Hey, @Rocketknight1. I see that you removed the 1 failing test in this PR: https://github.com/huggingface/transformers/pull/42515. Thanks!
I think the current failing tests (ERROR: Worker crash detected in test output) seems un-related.

Yeah, it's unrelated. We're working on fixing that part of the CI too!

> Yeah, it's unrelated. We're working on fixing that part of the CI too!

@Rocketknight1 This CI issue is fixed. The Failing test looks un-related to the PR.

@Sai-Suraj-27 after #42522, do we still the fix in this PR?

> @Sai-Suraj-27 after #42522, do we still the fix in this PR?

Hey, @ydshieh thanks for the review. 

After #42522, The test will pass without this PR, but since `convert_batch_to_list_format` is a staticmethod of the class, ideally the recommended way to call it is through the class: (`TokenizerTesterMixin.convert_batch_to_list_format(...)`) instead of through `self`. So, I still feel this change reflects the recommended usage for static methods.