Expose duration through DispatchInfo

Some dispatches need the duration to make an execution plan.

Signed-off-by: Sahas Subramanian <[email protected]>

Author: shsms

src/frequenz/dispatch/_actor_dispatcher.py

@@ -32,6 +32,9 @@ class DispatchInfo:
     options: dict[str, Any]
     """Additional options."""
 
+    duration: timedelta | None
+    """The duration of the dispatch."""
+
 
 class ActorDispatcher(BackgroundService):
     """Helper class to manage actors based on dispatches.
@@ -229,6 +232,7 @@ async def _start_actor(self, dispatch: Dispatch) -> None:
             components=dispatch.target,
             dry_run=dispatch.dry_run,
             options=dispatch.payload,
+            duration=dispatch.duration,
         )
 
         identity = self._dispatch_identity(dispatch)