Re-enable squad test
# What does this PR do?

This re-enables the squad test which was skipped while Accelerate was getting fixed. Will merge when all is green.

This also fixes the `[all-test]` directive which was broken by the recent changes for examples in the test fetcher.
_The documentation is not available anymore as the PR was closed or merged._<|||||>The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_23912). All of your documentation changes will be reflected on that endpoint.