Remove deprecated max_size support from YOLOS image processor

[kartickkt]

• Updated test_image_processor_from_dict_with_kwargs to remove the deprecated max_size argument.
• Uses only {"shortest_edge": ...} in size, consistent with current API.
• Ensures compatibility with the latest image processor spec.

Before submitting

• Did you read the contributor guideline, Pull Request section?
• Did you write any new necessary tests?

All tests passed locally using pytest tests/models/yolos/test_image_processing_yolos.py.

[kartickkt]

All checks have passed.
Branch is now up-to-date. Ready for review.
Happy to help further if needed!

[Rocketknight1]

cc @qubvel @yonigozlan