chore: consolidate is_in_favs() methods

dzgui/controllers/mc.py

@@ -2,7 +2,6 @@ import inspect
 import logging
 
 from typing import Any, Callable, TYPE_CHECKING
-from warnings import deprecated
 
 import dzgui.util._json as JSON  # noqa
 
@@ -373,9 +372,6 @@ class Controller(GObject.GObject):
             return False
         return True
 
-    # def is_in_favs(self) -> bool:
-    #    return self.config_man.is_in_favs()
-
     def get_config_man(self) -> ConfigManager:
         return self.config_man