Add BioGptForSequenceClassification
# What does this PR do?

Fixes #21530

## 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#start-contributing-pull-requests),
      Pull Request section?
- [x] 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.
- [x] 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).
- [x] Did you write any new necessary tests?


## Who can review?

@NielsRogge

The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_21535). All of your documentation changes will be reflected on that endpoint.<|||||>Hi, it seems the CI didn't run properly. Could you push an empty commit to trigger it?<|||||>What Niels forgot to say is that there seems to be an issue with your CircleCI permissions, the tests won't run.
Could you try refreshing your permissions as shown [here](https://support.circleci.com/hc/en-us/articles/360048210711-How-to-Refresh-User-Permissions-) and then push some commit to your PR?<|||||>> What Niels forgot to say is that there seems to be an issue with your CircleCI permissions, the tests won't run. Could you try refreshing your permissions as shown [here](https://support.circleci.com/hc/en-us/articles/360048210711-How-to-Refresh-User-Permissions-) and then push some commit to your PR?

I tried but it didn't work 😖 
<|||||>Hi @GuillemGSubies. If the issue is still open, i would like to contribute it.
Thanks<|||||>@upjabir I don't understand why the pipelines fail, you have any idea? Otherwise you can open another PR and I'll close this one<|||||>@GuillemGSubies currently I don't have any idea about the issue. But let me try it, so I can get a clear picture<|||||>This issue has been automatically marked as stale because it has not had recent activity. If you think this still needs to be addressed please comment on this thread.

Please note that issues that do not follow the [contributing guidelines](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md) are likely to be ignored.