made tokenization_roformer independent of bert
Author: naveennamani
Pull request: yes

# What does this PR do?
Relates to issue #19303 

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Fixes #19303 


## Before submitting
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@patrickvonplaten 

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Models:

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HF projects:

- datasets: [different repo](https://github.com/huggingface/datasets)
- rust tokenizers: [different repo](https://github.com/huggingface/tokenizers)

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Comments:
_The documentation is not available anymore as the PR was closed or merged._

Gently pinging @sgugger @ArthurZucker for re-distribution here 

Will take care of it 👍

Don't worrk @ArthurZucker I'll review :-) This is linked to #19303 and I should have been tagged, not Patrick :-)

@sgugger when I opened the PR, in the PR template it showed me @patrickvonplaten is looking after roformer which I modified, so tagged him for the review.

No worries at all @naveennamani , but as @patrickvonplaten is very busy on plenty of other things and you PR should not make any actual changes so Patrck's input won't be necessary. I'll review it tomorrow :-)

Hi @sgugger , I've modified the comments as per your suggestion.

I missed it somehow, fixed it