⚖️ Add tests_latest.yml workflow file

[qgallouedec]

What does this PR do?

This workflow tests the latest version of TRL (currently in branch v0.12-release) daily to ensure compatibility with the development versions of required dependencies (datasets, accelerate, and transformers).

By running these tests, we can quickly identify and address breaking changes in these libraries before they are released.

This workflow currently fails because we removed old tiny models as part of #2287.

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,
  Pull Request section?
• Was this discussed/approved via a GitHub issue? 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.
• Did you write any new necessary tests?

Who can review?

Anyone in the community is free to review the PR once the tests have passed. Feel free to tag
members/contributors who may be interested in your PR.

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.