[Bugfix] Validate lora adapters to avoid crashing server (#11727)

Signed-off-by: Joe Runde <Joseph.Runde@ibm.com>
Co-authored-by: Jee Jee Li <pandaleefree@gmail.com>

vllm/engine/async_llm_engine.py

@@ -1257,6 +1257,10 @@ class AsyncLLMEngine(EngineClient):
         else:
             self.engine.model_executor._run_workers("stop_profile")
 
+    async def add_lora(self, lora_request: LoRARequest) -> None:
+        """Load a new LoRA adapter into the engine for future requests."""
+        self.engine.add_lora(lora_request)
+
 
 # TODO(v1): Remove this class proxy when V1 goes default.
 if envs.VLLM_USE_V1: