Nesting combine should preserve window_for_dispatch

kitty/boss.py

@@ -1620,6 +1620,7 @@ def combine(self, action_definition: str, window_for_dispatch: Optional[Window]
                 self.show_error('Failed to parse action', f'{action_definition}\n{e}')
                 return True
             if actions:
+                window_for_dispatch = window_for_dispatch or self.window_for_dispatch
                 try:
                     if self.dispatch_action(actions[0], window_for_dispatch, dispatch_type):
                         consumed = True