fix bart compatibility with numpy tensors
Author: kventinel
Pull request: yes

# What does this PR do?

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Changes only on `modeling_bart.py` file. Other changes just by copying mechanics.

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- [ ] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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Models:

- albert, bert, xlm: @LysandreJik
- blenderbot, bart, marian, pegasus, encoderdecoder,  t5: @patrickvonplaten, @patil-suraj
- longformer, reformer, transfoxl, xlnet: @patrickvonplaten
- fsmt: @stas00
- funnel: @sgugger
- gpt2: @patrickvonplaten, @LysandreJik
- rag: @patrickvonplaten, @lhoestq
- tensorflow: @LysandreJik

Library:

- benchmarks: @patrickvonplaten
- deepspeed: @stas00
- ray/raytune: @richardliaw, @amogkam
- text generation: @patrickvonplaten
- tokenizers: @n1t0, @LysandreJik
- trainer: @sgugger
- pipelines: @LysandreJik

Documentation: @sgugger

HF projects:

- datasets: [different repo](https://github.com/huggingface/datasets)
- rust tokenizers: [different repo](https://github.com/huggingface/tokenizers)

Examples:

- maintained examples (not research project or legacy): @sgugger, @patil-suraj
- research_projects/bert-loses-patience: @JetRunner
- research_projects/distillation: @VictorSanh

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Comments:
The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_19826). All of your documentation changes will be reflected on that endpoint.

Thanks for your PR, but PyTorch models do not accept NumPy arrays as inputs, and your changes won't make any difference for that I believe.

> but PyTorch models do not accept NumPy arrays as inputs, and your changes won't make any difference for that I believe.

Yep, it's true. But in most of this cases would be produced more clear error than `'int' object is not callable` caused by `size` property of numpy array

@sgugger, ping

I think I have been pretty clear on why we don't want this change. PyTorch models do not support NumPy arrays and we are not interested in replacing all the `size()` by `shape`.

> I think I have been pretty clear on why we don't want this change. PyTorch models do not support NumPy arrays and we are not interested in replacing all the `size()` by `shape`.

Yep, I understand it. This PR only about more clear errors on numpy tensors. Nothing else. So I think it's make little easier to debug.

@sgugger, ping

This issue has been automatically marked as stale because it has not had recent activity. If you think this still needs to be addressed please comment on this thread.

Please note that issues that do not follow the [contributing guidelines](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md) are likely to be ignored.