fix(mmgen): align trajectory_timesteps type annotations

Author: MikukuOvO

python/sglang/multimodal_gen/runtime/pipelines_core/schedule_batch.py

@@ -133,7 +133,7 @@ class Req:
     # Component modules (populated by the pipeline)
     modules: dict[str, Any] = field(default_factory=dict)
 
-    trajectory_timesteps: list[torch.Tensor] | None = None
+    trajectory_timesteps: torch.Tensor | None = None
     trajectory_latents: torch.Tensor | None = None
     trajectory_log_probs: torch.Tensor | None = None
     trajectory_audio_latents: torch.Tensor | None = None
@@ -332,7 +332,7 @@ class OutputBatch:
     output: torch.Tensor | None = None
     audio: torch.Tensor | None = None
     audio_sample_rate: int | None = None
-    trajectory_timesteps: list[torch.Tensor] | None = None
+    trajectory_timesteps: torch.Tensor | None = None
     trajectory_latents: torch.Tensor | None = None
     trajectory_log_probs: torch.Tensor | None = None
     trajectory_decoded: list[torch.Tensor] | None = None