Fix: 'Gemma2Attention' object has no attribute '_flash_attn_uses_top_left_mask'
Author: jp1924
Pull request: yes

# What does this PR do?
A PR to fix the 'no attribute '_flash_attn_uses_top_left_mask'' error occurring in each model with the flash_attention module, including gemma2.
## Reproduction Code
```python
from transformers import AutoConfig, AutoModelForCausalLM, AutoTokenizer


def main() -> None:
    repo_id = "google/gemma-2-2b-it"
    config = AutoConfig.from_pretrained(repo_id, _attn_implementation="flash_attention_2")
    model = AutoModelForCausalLM.from_pretrained(repo_id, config=config, device_map="cpu")
    tokenizer = AutoTokenizer.from_pretrained(repo_id)

    text = tokenizer.apply_chat_template([{"role": "user", "content": "Hello!"}], tokenize=False)
    input_param = tokenizer(text, return_tensors="pt", return_attention_mask=True)
    input_param["labels"] = input_param["input_ids"].clone()
    output = model(**input_param)


if "__main__" in __name__:
    main()

```
> pip install git+https://github.com/huggingface/transformers.git@5615a393691c81e00251e420c73e4d04c6fe22e5
## Env
```
- `transformers` version: 4.48.0.dev0
- Platform: Linux-5.15.0-124-generic-x86_64-with-glibc2.35
- Python version: 3.10.12
- Huggingface_hub version: 0.26.2
- Safetensors version: 0.4.5
- Accelerate version: 1.1.1
```


## Before submitting
- [ ] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
- [ ] 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

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Comments:
@ArthurZucker
the attention module is being included in the config. Is this working as you intended?

This pull request is being closed because the issue has been resolved in pull request #35235.

Thanks ! And sorry for the delay! 🤗