[Core] V1: Use multiprocessing by default (#11074)

Signed-off-by: Russell Bryant <rbryant@redhat.com>

vllm/entrypoints/llm.py

@@ -232,6 +232,10 @@ class LLM:
 
         self.request_counter = Counter()
 
+    def __del__(self):
+        if self.llm_engine and hasattr(self.llm_engine, "shutdown"):
+            self.llm_engine.shutdown()
+
     @staticmethod
     def get_engine_class() -> Type[LLMEngine]:
         if envs.VLLM_USE_V1: