Added Type hints for VIT MAE
Based on Issue #16059 

While looking through the codebase, I found that the ViTMAE model doesn't had the type hints as suggested in Issue #16059. Added type hints for [ViTMAEModel](https://huggingface.co/docs/transformers/model_doc/vit_mae#transformers.ViTMAEModel) and [ViTMAEForPreTraining](https://huggingface.co/docs/transformers/model_doc/vit_mae#transformers.ViTMAEForPreTraining) models.

@Rocketknight1 Could you kindly check if this is fine?

Thanks in advance.
_The documentation is not available anymore as the PR was closed or merged._<|||||>Thanks @Rocketknight1.