Add ImageProcessorFast to BiT processor
Author: Yann-CV
Pull request: yes

# What does this PR do?

Following https://github.com/huggingface/transformers/issues/36978:

This pull request introduces a new fast image processor class for the BiT model along with the necessary updates to integrate it into the existing codebase. The most important changes include the addition of the `BitImageProcessorFast` class, modifications to the initialization and import structures, and updates to the documentation and tests.

### New Feature Addition:
* [`src/transformers/models/bit/image_processing_bit_fast.py`](diffhunk://#diff-351beedf180b467145940c5f6e809b0ff034eb93a564d49ec7da4bb4003bd0d7R1-R59): Added the new `BitImageProcessorFast` class, which includes methods for preprocessing images with various settings and parameters.

### Integration Updates:
* [`src/transformers/__init__.py`](diffhunk://#diff-7723156f6b075b1bf1525f769d90a7cc0b5f233becdcbe28707aaa753960d897R1348): Updated the import structure to include `BitImageProcessorFast` in the `models.bit` module. [[1]](diffhunk://#diff-7723156f6b075b1bf1525f769d90a7cc0b5f233becdcbe28707aaa753960d897R1348) [[2]](diffhunk://#diff-7723156f6b075b1bf1525f769d90a7cc0b5f233becdcbe28707aaa753960d897R6641)
* [`src/transformers/models/auto/image_processing_auto.py`](diffhunk://#diff-dc5c050927ed279b77bac41443778a1155c1cd7825aae50412d70b65bb96397fL61-R61): Added `BitImageProcessorFast` to the list of image processors for the `bit` model. [[1]](diffhunk://#diff-dc5c050927ed279b77bac41443778a1155c1cd7825aae50412d70b65bb96397fL61-R61) [[2]](diffhunk://#diff-dc5c050927ed279b77bac41443778a1155c1cd7825aae50412d70b65bb96397fL81-R95)
* [`src/transformers/models/bit/__init__.py`](diffhunk://#diff-2cff440fc284a759da756f46aeb80c4d86f34690d2ae5e67878f2fe06e3b4382R23): Included `BitImageProcessorFast` in the type checking imports.

### Documentation Updates:
* `docs/source/en/model_doc/bit.md` and `docs/source/ja/model_doc/bit.md`: Added documentation entries for the new `BitImageProcessorFast` class. [[1]](diffhunk://#diff-baa34b2511c05dceaf27e94a1b42a3cb65155958207eaf23997bc46aa6299e97R61-R65) [[2]](diffhunk://#diff-ca7bacda9902808adc6d6c009db15c3df79465cf380a77dc4ded7820b87dc09bR57-R61)

### Testing:
* [`tests/models/bit/test_image_processing_bit.py`](diffhunk://#diff-43451340d4a1ee4fe3d69a2555b3a9d65dece62f135eb59e4bca16e16a9f8c69R1-R104): Added unit tests for `BitImageProcessorFast` to ensure proper functionality and integration.

### Dummy Objects:
* [`src/transformers/utils/dummy_torchvision_objects.py`](diffhunk://#diff-628ebb72d86e41f003144eae7255f5f0e9e60bbf5cb742b5b5447a0360cf1968R12-R18): Added a dummy class for `BitImageProcessorFast` to handle cases where `torchvision` is not available.


## 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#create-a-pull-request),
      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.
- [x] 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).
- [x] Did you write any new necessary tests?





Comments:
do not know why test are taking forever

@yann-cv try rebasing to trigger the tests if they don't start automatically once you mark it ready for review!

worked thanks @Rocketknight1 

@ydshieh @yonigozlan this one looks ready to be reviewed

@yonigozlan should be good now

The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_37180). All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.