Revert create_timer change

Author: andystaples

durabletask/task.py

@@ -98,7 +98,7 @@ def set_custom_status(self, custom_status: Any) -> None:
         pass
 
     @abstractmethod
-    def create_timer(self, fire_at: Union[datetime, timedelta]) -> TimerTask:
+    def create_timer(self, fire_at: Union[datetime, timedelta]) -> Task:
         """Create a Timer Task to fire after at the specified deadline.
 
         Parameters

durabletask/worker.py

@@ -1007,7 +1007,7 @@ def set_custom_status(self, custom_status: Any) -> None:
             shared.to_json(custom_status) if custom_status is not None else None
         )
 
-    def create_timer(self, fire_at: Union[datetime, timedelta]) -> task.TimerTask:
+    def create_timer(self, fire_at: Union[datetime, timedelta]) -> task.Task:
         return self.create_timer_internal(fire_at)
 
     def create_timer_internal(