Remove Roberta Dependencies from XLM Roberta Flax and Tensorflow models
# What does this PR do?

This removes Roberta dependencies from XLM Roberta Flax and Tensorflow Models.

I'm a bit confused about whether the `name` parameter to `TFXLMRobertaMainLayer` should be `xml-roberta` or `xml_roberta` - I've gome with `xml-roberta` for now.
i.e. `self.XLMRoberta = TFXLMRobertaMainLayer(config, name="xlm-roberta")`

Fixes #19303

## Before submitting
- [ ] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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      Pull Request section?
- [X ] Was this discussed/approved via a Github issue or the [forum](https://discuss.huggingface.co/)? Please add a link
      to it if that's the case.
- [ ] Did you make sure to update the documentation with your changes? Here are the
      [documentation guidelines](https://github.com/huggingface/transformers/tree/main/docs), and
      [here are tips on formatting docstrings](https://github.com/huggingface/transformers/tree/main/docs#writing-source-documentation).
- [ ] Did you write any new necessary tests?


## Who can review?
@sgugger 
_The documentation is not available anymore as the PR was closed or merged._<|||||>Thanks! There are a couple of places where the copy does not match the original. You can test locally with `make repo-consistency` to get the failing tests. Let me know if you need help!<|||||>HI @sgugger, thanks for the advice! I've tried `make repo-consistency` but it looks like the version of jax that was installed during `pip -e ".[dev]"` causes `RuntimeError: jaxlib is version 0.1.75, but this version of jax requires version >= 0.3.0.`<|||||>Ah, it's a problem with my original dev install. I'll reinstall and see how it goes.<|||||>I can't figure out this last copy error, could you help me out? Thanks.<|||||>I won't be able to dive more into it until next week. Running `make fix-copies` and looking at the diff will give you a clue of what the copies util wants to change.<|||||>Got it, thanks for the tip<|||||>@sgugger I'm stuck on this error message as a part of `make repo-consistency`: 
```
python utils/check_inits.py
Traceback (most recent call last):
  File "/home/ziggy/dev/transformers/utils/check_inits.py", line 299, in <module>
    check_all_inits()
  File "/home/ziggy/dev/transformers/utils/check_inits.py", line 238, in check_all_inits
    raise ValueError("\n\n".join(failures))
ValueError: Problem in src/transformers/__init__.py, both halves do not define the same objects.
Differences for tf backend:
  TFXLMRobertaForCausalLM in _import_structure but not in TYPE_HINT.
  TFXLMRobertaPreTrainedModel in _import_structure but not in TYPE_HINT.
Differences for flax backend:
  FlaxXLMRobertaForCausalLM in _import_structure but not in TYPE_HINT.
  FlaxXLMRobertaPreTrainedModel in _import_structure but not in TYPE_HINT.

Problem in src/transformers/models/xlm_roberta/__init__.py, both halves do not define the same objects.
Differences for flax backend:
  FLAX_XLM_ROBERTA_PRETRAINED_MODEL_ARCHIVE_LIST in TYPE_HINT but not in _import_structure.
make: *** [Makefile:41: repo-consistency] Error 1
```

I don't know where the variable `TYPE_HINT` is, it doesn't seem to be anywhere in the entire repo apart from this error message.<|||||>Ah never mind, I found them. Thanks!<|||||>I'm confused by the error that's showing now - the doc builder can't find `TFXLMRobertaForCausalLM.forward` , which I don't think exists because it's tensorflow...<|||||>Finally, no errors 😆 <|||||>Thanks so much for all the help!