Replace deprecated use of 'Repository' when pushing to hub with `HfApi`

[cochaviz]

Remove deprecated use of 'Repository' when pushing to huggingface hub

Description

As mentioned above, use of the Repository class is deprecated: https://hu…ggingface.co/docs/huggingface_hub/concepts/git_vs_http.

Motivation and Context

• [x] I have raised an issue to propose this change (required for new features and bug fixes)

Closes #463 🥳

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Documentation (update in the documentation)

Checklist:

• [x] I've read the CONTRIBUTION guide (required)
• [x] I have updated the changelog accordingly (required).
• [ ] My change requires a change to the documentation.
• [x] I have updated the tests accordingly (required for a bug fix or a new feature).
• [ ] I have updated the documentation accordingly.
• [x] I have reformatted the code using make format (required)
• [x] I have checked the codestyle using make check-codestyle and make lint (required)
• [x] I have ensured make pytest and make type both pass. (required)

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