Fix flaky playlists navigation test
See: https://github.com/ppy/osu/actions/runs/16267403227/job/45929099025
Repro:
```diff
diff --git a/osu.Game/Screens/OnlinePlay/Lounge/LoungeSubScreen.cs b/osu.Game/Screens/OnlinePlay/Lounge/LoungeSubScreen.cs
index a4e808ff76..db0a0e83a6 100644
--- a/osu.Game/Screens/OnlinePlay/Lounge/LoungeSubScreen.cs
+++ b/osu.Game/Screens/OnlinePlay/Lounge/LoungeSubScreen.cs
@@ -88,6 +88,7 @@ public abstract partial class LoungeSubScreen : OnlinePlaySubScreen, IOnlinePlay
[BackgroundDependencyLoader(true)]
private void load()
{
+ System.Threading.Thread.Sleep(1000);
Masking = true;
const float controls_area_height = 25f;
```