Replace loadbp usages with loadmap (#6085)

Content.Server/Maps/GameMapManager.cs

@@ -21,7 +21,6 @@ public class GameMapManager : IGameMapManager
     [Dependency] private readonly IPlayerManager _playerManager = default!;
     [Dependency] private readonly IRobustRandom _random = default!;
     [Dependency] private readonly IChatManager _chatManager = default!;
-    [Dependency] private readonly IMapLoader _mapLoader = default!;
 
     private GameMapPrototype _currentMap = default!;
     private bool _currentMapForced;