Correct LocalTrailerCount in API

Revert a change which resulted in the `LocalTrailerCount` including the count of Local and Remote trailers which had been introduced in 10.8.

Emby.Server.Implementations/Dto/DtoService.cs

@@ -1094,7 +1094,7 @@ namespace Emby.Server.Implementations.Dto
             {
                 if (item is IHasTrailers hasTrailers)
                 {
-                    dto.LocalTrailerCount = hasTrailers.GetTrailerCount();
+                    dto.LocalTrailerCount = (item as IHasTrailers).LocalTrailers.Count;
                 }
                 else
                 {