Adding Type Hints to TF_Pegasus model
# What does this PR do?

Added type hints for remaining `call()` functions for the Pegasus model (changes made only in the models/pegasus/modeling_tf_pegasus.py file). 


Fixes # [(16059)](https://github.com/huggingface/transformers/issues/16059)


## Before submitting
- [ ] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
- [x] Did you read the [contributor guideline](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md#start-contributing-pull-requests),
      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.
[approval](https://github.com/huggingface/transformers/issues/16059#issuecomment-1441895896)
- [ ] 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?

Anyone in the community is free to review the PR once the tests have passed. Feel free to tag
members/contributors who may be interested in your PR.

@Rocketknight1 

_The documentation is not available anymore as the PR was closed or merged._<|||||>Hi @mollerup23, mostly looks good! One thing to watch out for is that in some cases the default value of the argument has been changed. It's easy to see if you look in the GitHub "Files changed" tab (see the image - `return_dict` had its default argument changed)
![image](https://user-images.githubusercontent.com/12866554/223161978-7abf2912-865d-4975-80bb-f38899440350.png)

If you fix the instances where that happened and double-check that it's all okay in the Files Changed tab, we should be good to go!<|||||>Hi @Rocketknight1, I updated and committed again. Hopefully these fixes help, let me know if there is anything else I should do!