Remove unused AudioMixTarget code. (#3838)

* Remove unused AudioMixTarget code.

* Update submodule

Co-authored-by: metalgearsloth <comedian_vs_clown@hotmail.com>

Content.Client/GameObjects/Components/Mobs/ICharacterUI.cs

@@ -9,7 +9,7 @@ namespace Content.Client.GameObjects.Components.Mobs
     public interface ICharacterUI
     {
         /// <summary>
-        /// The godot control which holds the character user interface to be included in the window
+        /// The control which holds the character user interface to be included in the window
         /// </summary>
         Control Scene { get; }