Add LLaVa NeXT Video (#31252)

* squash into single commit

* run diff once more

* docstring

* tests

* minor chnages and ready to go

* Update src/transformers/models/llava_next_video/processing_llava_next_video.py

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

* Update tests/models/vipllava/test_modeling_vipllava.py

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

* [run-slow] llava-next-video

* [run-slow] llava-next-video

* [run-slow] llava_next_video

* fix two tests

* fix slow tests

* remove logit checks due to numeric errors

* run test once more

* [run-slow] llava_next_video

* final try to pass the test

* [run-slow] llava_next_video

* [run-slow] llava_next_video

* [run-slow] llava_next_video

* style

* fix

* style

---------

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

docs/source/en/_toctree.yml

@@ -794,6 +794,8 @@
         title: Llava
       - local: model_doc/llava_next
         title: LLaVA-NeXT
+      - local: model_doc/llava-next-video
+        title: LLaVa-NeXT-Video
       - local: model_doc/lxmert
         title: LXMERT
       - local: model_doc/matcha