Clarify type of value depends on option in setopt

Co-authored-by: Sebastian Rittau <sebastian.rittau@zfutura.de>

Author: aeroyorch

stubs/pycurl/pycurl/async_multi.pyi

@@ -8,7 +8,7 @@ from pycurl._pycurl import Curl
 
 class AsyncCurlMulti:
     def __init__(self, close_handles: bool = False) -> None: ...
-    def setopt(self, option: int, value: Any) -> None: ...
+    def setopt(self, option: int, value: Any) -> None: ...  # type of value depends on the option
     def add_handle(self, curl: Curl) -> asyncio.Future[Curl]: ...
     def remove_handle(self, curl: Curl) -> None: ...
     async def perform(self, curl: Curl) -> Curl: ...