Fix `.push_to_hub` and cleanup `get_full_repo_name` usage
A few (vaguely) related changes in this PR. The main goal was to fix a bug when `.push_to_hub` is used with a repo_id in the form `"organization/repo_name"` that is also a local working directory. The organization gets removed which pushes the model to `"username/repo_name"` instead of under the organization. This bug has been reported [on slack](https://huggingface.slack.com/archives/C02EMARJ65P/p1690366443112179) (private link) by @NathanHB. In addition to this fix, I also made some changes to get rid of `get_full_repo_name` in most cases.

**List of changes:**
- fix `src/transformers/utils/hub.py` to work with organization (bug above)
- added some ValueError when using deprecated args in addition to existing args
- get rid of `get_full_repo_name` in training scripts (no need for it when using `create_repo`),  which saves 1 whoami call
- removed `get_full_repo_name` from keras_callback.py, modeling_tf_utils.py and trainer.py
- import `get_full_repo_name` from `huggingface_hub` instead of re-defining it.

I expect nothing to be broken by those changes.
_The documentation is not available anymore as the PR was closed or merged._<|||||>Thanks for the review @ydshieh. I added some comments and fix a bug where token was not used (well done finding this one! :wink:). So I think we're good to go now. I'll merge the PR once CI is green :) <|||||>@Wauplin Thanks for the update. Good to merge (you can re-run the failed tests and it should be fine).

Regarding the comment, thanks a lot. (What I originally mean is that adding some comments on the PR pages, but it could be on the code too.)

<|||||>~@ydshieh I don't think I have the permissions to rerun a failed test. Could you trigger it for me please :pray:~

**EDIT:** I was logged out :smile: I just triggered it.
