Simplify sample invocation code

Author: AnatoliB

samples-v2/openai_agents/function_app.py

@@ -3,6 +3,7 @@
 from durable_decorators import durable_openai_agent_orchestrator
 from model_activity import create_invoke_model_activity
 
+import basic.hello_world
 
 app = func.FunctionApp(http_auth_level=func.AuthLevel.FUNCTION)
 
@@ -22,6 +23,4 @@ async def orchestration_starter(req: func.HttpRequest, client):
 @app.orchestration_trigger(context_name="context")
 @durable_openai_agent_orchestrator
 def basic_hello_world_orchestrator(context):
-    from basic.hello_world import main
-    result = main()
-    return result
+    return basic.hello_world.main()