fix: use lod-style Optional for case Optional[None]

Author: danfimov

taskiq/cli/worker/process_manager.py

@@ -9,7 +9,7 @@
 from multiprocessing.synchronize import Event as EventType
 from pathlib import Path
 from time import sleep
-from typing import Any
+from typing import Any, Optional
 
 try:
     from watchdog.observers import Observer
@@ -159,7 +159,7 @@ def __init__(
         self,
         args: WorkerArgs,
         worker_function: Callable[[WorkerArgs], None],
-        observer: Observer | None = None,  # type: ignore[valid-type]
+        observer: Optional[Observer] = None,  # type: ignore[valid-type] # noqa: UP045
     ) -> None:
         self.worker_function = worker_function
         self.action_queue: Queue[ProcessActionBase] = Queue(-1)