[V1][Minor] Restore V1 compatibility with LLMEngine class

The check was added to AsyncLLMEngine but not LLMEngine.

Signed-off-by: Thibault Schueller <[email protected]>

Signed-off-by: 'Thibault Schueller' <'[email protected]'>

Author: Ryp

vllm/engine/llm_engine.py

@@ -2028,3 +2028,8 @@ def _build_logits_processors(
                 sampling_params.logits_processors.extend(logits_processors)
 
         return sampling_params
+
+
+# TODO(v1): Remove this class proxy when V1 goes default.
+if envs.VLLM_USE_V1:
+    from vllm.v1.engine.llm_engine import LLMEngine  # type: ignore