Order MediaStream query by StreamIndex (#13506)

Our stream index calculation logic implemented in #7529, assumes an in-order array. However, our current query may return out-of-order items, leading the server to pass an incorrect index to ffmpeg, causing the transcoding to crash.

Jellyfin.Server.Implementations/Item/MediaStreamRepository.cs

@@ -88,7 +88,7 @@ public class MediaStreamRepository : IMediaStreamRepository
             query = query.Where(e => e.StreamType == typeValue);
         }
 
-        return query;
+        return query.OrderBy(e => e.StreamIndex);
     }
 
     private MediaStream Map(MediaStreamInfo entity)