[V1] Avoid socket errors during shutdown when requests are in in-flight (#16807)

Signed-off-by: Nick Hill <nhill@redhat.com>

vllm/v1/engine/core.py

@@ -384,7 +384,7 @@ class EngineCoreProc(EngineCore):
 
         except SystemExit:
             logger.debug("EngineCore exiting.")
-
+            raise
         except Exception as e:
             if engine_core is None:
                 logger.exception("EngineCore failed to start.")