Pin TensorFlow as new release breaks `pip install transformers["all"]`
# What does this PR do?

This PR pins TensorFlow for now, as it seems there is no version of `tensorflow-text` compatible with it.
Merging as it unlocks the styling checks, will further fix the rest of the failing tests in a separate PR.<|||||>The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_20313). All of your documentation changes will be reflected on that endpoint.