Add LLaVa-1.6, bis (#29586)

* First draft

* Fix tests, add docs

* Improve docstrings

* Fix test

* Address comments

* Address comments

* Remove vocab_size attribute

* Remove batch_size

* Address comment

* Add image processor tests

* Support fx

* Update docstring

* Add support for 34b

* Convert 34b model

* Add integration tests

* Update checkpoints

* Convert vicuna-13b, remove doc tests

* Remove script

* Remove file

* Address comments

* Improve docstrings

* Deprecate vocab_size

* Remove aspect_ratio_setting

* Address comments

* Update READMEs

* Add tips about chat templates

* Fix tests

* Deprecate vocab_size safely

* Update tests

---------

Co-authored-by: Amy Roberts <22614925+amyeroberts@users.noreply.github.com>

docs/source/en/perf_infer_gpu_one.md

@@ -49,6 +49,7 @@ FlashAttention-2 is currently supported for the following architectures:
 * [Falcon](https://huggingface.co/docs/transformers/model_doc/falcon#transformers.FalconModel)
 * [Llama](https://huggingface.co/docs/transformers/model_doc/llama#transformers.LlamaModel)
 * [Llava](https://huggingface.co/docs/transformers/model_doc/llava)
+* [Llava-NeXT](https://huggingface.co/docs/transformers/model_doc/llava_next)
 * [VipLlava](https://huggingface.co/docs/transformers/model_doc/vipllava)
 * [MBart](https://huggingface.co/docs/transformers/model_doc/mbart#transformers.MBartModel)
 * [Mistral](https://huggingface.co/docs/transformers/model_doc/mistral#transformers.MistralModel)