Revert scheduler to UniPCMultistepScheduler (RCM is set at runtime by pipeline)

model_index.json

@@ -2,8 +2,8 @@
   "_class_name": "TurboDiffusionPipeline",
   "_diffusers_version": "0.33.0.dev0",
   "scheduler": [
-    "fastvideo.models.schedulers",
-    "RCMScheduler"
+    "diffusers",
+    "UniPCMultistepScheduler"
   ],
   "text_encoder": [
     "transformers",
@@ -21,4 +21,4 @@
     "diffusers",
     "AutoencoderKLWan"
   ]
-}
+}