LTX Video 0.9.8 long multi prompt (#12614)
* LTX Video 0.9.8 long multi prompt
* Further align comfyui
- Added the “LTXEulerAncestralRFScheduler” scheduler, aligned with [sample_euler_ancestral_RF](https://github.com/comfyanonymous/ComfyUI/blob/7d6103325e1c97aa54f963253e3e7f1d6da6947f/comfy/k_diffusion/sampling.py#L234)
- Updated the LTXI2VLongMultiPromptPipeline.from_pretrained() method:
- Now uses LTXEulerAncestralRFScheduler by default, for better compatibility with the ComfyUI LTXV workflow.
- Changed the default value of cond_strength from 1.0 to 0.5, aligning with ComfyUI’s default.
- Optimized cross-window overlap blending: moved the latent-space guidance injection to before the UNet and after each step, aligned with[KSamplerX0Inpaint]([ComfyUI/comfy/samplers.py at master · comfyanonymous/ComfyUI](https://github.com/comfyanonymous/ComfyUI/blob/master/comfy/samplers.py#L391))
- Adjusted the default value of skip_steps_sigma_threshold to 1.
* align with diffusers contribute rule
* Add new pipelines and update imports
* Enhance LTXI2VLongMultiPromptPipeline with noise rescaling
Refactor LTXI2VLongMultiPromptPipeline to improve documentation and add noise rescaling functionality.
* Clean up comments in scheduling_ltx_euler_ancestral_rf.py
Removed design notes and limitations from the implementation.
* Enhance video generation example with scheduler
Updated LTXI2VLongMultiPromptPipeline example to include LTXEulerAncestralRFScheduler for ComfyUI parity.
* clean up
* style
* copies
* import ltx scheduler
* copies
* fix
* fix more
* up up
* up up up
* up upup
* Apply suggestions from code review
* Update docs/source/en/api/pipelines/ltx_video.md
* Update docs/source/en/api/pipelines/ltx_video.md
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Co-authored-by: yiyixuxu <yixu310@gmail.com>
