fix: remove artifact parameter of _process_async

transitions/extensions/asyncio.pyi

@@ -117,7 +117,7 @@ class AsyncMachine(Machine):
     def get_state(self, state: Union[str, Enum]) -> AsyncState: ...
     async def process_context(self, func: Callable[[], Awaitable[None]], model: object) -> bool: ...
     def remove_model(self, model: object) -> None: ...
-    async def _process_async(self, trigger: Callable[[], Awaitable[None]], model: object, queued: bool) -> bool: ...
+    async def _process_async(self, trigger: Callable[[], Awaitable[None]], model: object) -> bool: ...
 
 
 class HierarchicalAsyncMachine(HierarchicalMachine, AsyncMachine):  # type: ignore