Added Annotations for PyTorch models

[anmolsjoshi]

What does this PR do?

Adds annotations as described in #16059:

• Updated type annotations for CTRL (PT), RAG(PT)
• added type annotations for FSMT(PT), LED(PT), M2M(PT), MPNet(PT) , Nystromformer(PT), OpenAI(PT)

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• Did you write any new necessary tests?

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@sgugger

[HuggingFaceDocBuilderDev]

The documentation is not available anymore as the PR was closed or merged.

[anmolsjoshi]

@sgugger not sure why the tests are failing. I'm pretty sure they aren't related to added annotations

[sgugger]

Thanks for adding all of those!

[sgugger]

Thanks! We just need a last make style on your branch for the code quality check :-)