[Refactor] Unify the LTX-2 and LTX-2.3 pipeline runtime (#5147)

Signed-off-by: mglyn <1203789601@qq.com>

docs/user_guide/examples/online_serving/text_to_video.md

@@ -13,6 +13,7 @@ This example demonstrates how to deploy text-to-video models for online video ge
 | Wan2.1 T2V (14B) | `Wan-AI/Wan2.1-T2V-14B-Diffusers` |
 | Wan2.2 T2V | `Wan-AI/Wan2.2-T2V-A14B-Diffusers` |
 | LTX-2 | `Lightricks/LTX-2` |
+| LTX-2.3 | `diffusers/LTX-2.3-Diffusers` |
 
 ## Wan2.2 T2V
 
@@ -374,6 +375,17 @@ curl -sS -X POST http://localhost:8098/v1/videos \
   -F "seed=42"
 ```
 
+## LTX-2.3
+
+LTX-2.3 uses a Diffusers-format checkpoint and a dedicated pipeline class:
+
+```bash
+vllm serve diffusers/LTX-2.3-Diffusers --omni --port 8098 \
+    --model-class-name LTX23Pipeline
+```
+
+Send requests through the same `/v1/videos` API shown in the LTX-2 example.
+
 ## Example materials
 
 ??? abstract "response.json"