Update app.py

app.py

@@ -38,7 +38,7 @@ DEFAULT_API_URL = "https://agents-course-unit4-scoring.hf.space"
 # ----- THIS IS WHERE YOU CAN BUILD WHAT YOU WANT ------
 class BasicAgent:
     def __init__(self):
-        workflow = StateGraph(state: State)
+        workflow = StateGraph(State)
         workflow.add_node("assistant", assistant)
         workflow.add_node("tools", ToolNode([tools]))
         workflow.add_edge(START, "assistant")