fix(typing): session_reducer

Signed-off-by: Vigith Maurice <vigith@gmail.com>

Author: vigith

packages/pynumaflow-lite/pynumaflow_lite/session_reducer.pyi

@@ -42,7 +42,7 @@ class SessionReduceAsyncServer:
             info_file: str | None = ...,
     ) -> None: ...
 
-    def start(self, py_creator: type, init_args: tuple | None = ...) -> Awaitable[None]: ...
+    def start(self, py_creator: type[SessionReducer], init_args: tuple | None = ...) -> Awaitable[None]: ...
 
     def stop(self) -> None: ...