Remove unnecessary toolset function

Author: strawgate

tests/test_agent.py

@@ -3743,9 +3743,6 @@ def respond(messages: list[ModelMessage], info: AgentInfo) -> ModelResponse:
 async def test_toolset_decorator():
     toolset = FunctionToolset()
 
-    @toolset.tool
-    def foo() -> str: ...
-
     agent: Agent[None, str] = Agent('test')
 
     @agent.toolset