[V1] Update interface for idefics3

[ywang96]

Idefics3ForConditionalGeneration was left behind from #10570. This PR updates its interface to what we need in V1.

[github-actions]

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[ywang96]

This PR has been verified with

pytest tests/models/decoder_only/vision_language/test_models.py -k "idefics3"

and

python3 examples/offline_inference_vision_language.py -m idefics3