Use repo_type instead of deprecated datasets repo IDs
# What does this PR do?

In the next release of `huggingface_hub` trying to access any repo ID with the `"datasets/"` prefix will fail. `repo_type="dataset"` must be used instead.
This PR fixes all instances except for research projects.
Research projects are examples we do not actively maintain and pin all dependencies to a specific version.<|||||>_The documentation is not available anymore as the PR was closed or merged._