Calculate content height automatically

osu.Game/Screens/Select/Carousel/DrawableCarouselBeatmapSet.cs

@@ -70,7 +70,6 @@ namespace osu.Game.Screens.Select.Carousel
             Content.Add(beatmapContainer = new Container<DrawableCarouselItem>
             {
                 X = 100,
-                Y = MAX_HEIGHT,
                 RelativeSizeAxes = Axes.X,
                 AutoSizeAxes = Axes.Y,
             });

osu.Game/Screens/Select/Carousel/DrawableCarouselItem.cs

@@ -20,6 +20,9 @@ namespace osu.Game.Screens.Select.Carousel
 
         public readonly CarouselHeader Header;
 
+        /// <summary>
+        /// Optional content which sits below the header.
+        /// </summary>
         protected readonly Container<Drawable> Content;
 
         protected readonly Container MovementContainer;
@@ -89,6 +92,9 @@ namespace osu.Game.Screens.Select.Carousel
         {
             base.LoadComplete();
 
+            // avoid using fill flow for performance reasons. header size doesn't change after load.
+            Content.Y = Header.Height;
+
             UpdateItem();
         }