Fix tournament screen tests not matching OsuGameBase resolution

This would cause things to look completely out of whack.

The numbers here match `DrawSizePreservingFillContainer` defaults as
used by `OsuGameBase.CreateScalingContainer()`.

osu.Game.Tournament.Tests/TournamentScreenTestScene.cs

@@ -23,7 +23,7 @@ private partial class TournamentScalingContainer : DrawSizePreservingFillContain
         {
             public TournamentScalingContainer()
             {
-                TargetDrawSize = new Vector2(1920, 1080);
+                TargetDrawSize = new Vector2(1024, 768);
                 RelativeSizeAxes = Axes.Both;
             }