[Feature Extractors] Return attention mask always in int32
Author: patrickvonplaten
Pull request: yes

# What does this PR do?

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This PR fixes:

```
tests/test_modeling_tf_hubert.py::TFHubertModelIntegrationTest::test_inference_ctc_robust_batched
tests/test_modeling_tf_wav2vec2.py::TFWav2Vec2ModelIntegrationTest::test_inference_ctc_robust_batched
```

For some specific use cases the attention mask for feature extractors was returned to be of type `bool` which broke two tf slow tests. Make sure that it's always `int32` or `long` just like the tokenizers do for text. 



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Models:

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Comments:
LGTM! I think lots of stuff breaks with boolean attention masks, so we definitely want to avoid sending that to the model.