[Core] Some simplification of WorkerWrapper changes (#4183)

vllm/worker/worker_base.py

@@ -108,7 +108,8 @@ class WorkerWrapperBase:
         self.worker_class_name = worker_class_name
         self.worker = None
 
-    def update_environment_variables(self, envs: Dict[str, str]) -> None:
+    @staticmethod
+    def update_environment_variables(envs: Dict[str, str]) -> None:
         key = 'CUDA_VISIBLE_DEVICES'
         if key in envs and key in os.environ:
             # overwriting CUDA_VISIBLE_DEVICES is desired behavior
@@ -138,10 +139,8 @@ class WorkerWrapperBase:
 
     def execute_method(self, method, *args, **kwargs):
         try:
-            if hasattr(self, method):
-                executor = getattr(self, method)
-            else:
-                executor = getattr(self.worker, method)
+            target = self if self.worker is None else self.worker
+            executor = getattr(target, method)
             return executor(*args, **kwargs)
         except Exception as e:
             # if the driver worker also execute methods,