Update model_runner_v1.py

Author: ponix-j

vllm_ascend/worker/model_runner_v1.py

@@ -821,7 +821,7 @@ def get_spec_token_ids(
         num_scheduled_tokens: int,
         hidden_states: torch.Tensor,
         attn_metadata: SpecDecodeMetadata,
-    ) -> list[list[int]]:
+    ) -> Optional[list[list[int]]]:
         if not self.use_spec_decode:
             # Speculative decoding is not enabled.
             spec_token_ids = None