fix: CI errors - ModTimeRamp indexed access replaces FirstOrDefault, remove unused using in TestRoomRequestsHandler

Agent-Logs-Url: https://github.com/winnerspiros/osu/sessions/d1f89c95-e9d0-4a2a-98c2-097c91531c79

Co-authored-by: winnerspiros <1675249+winnerspiros@users.noreply.github.com>

Author: Copilot

osu.Game/Rulesets/Mods/ModTimeRamp.cs

@@ -82,7 +82,7 @@ public virtual void ApplyToBeatmap(IBeatmap beatmap)
         {
             SpeedChange.SetDefault();
 
-            double firstObjectStart = beatmap.HitObjects.FirstOrDefault()?.StartTime ?? 0;
+            double firstObjectStart = beatmap.HitObjects.Count > 0 ? beatmap.HitObjects[0].StartTime : 0;
             double lastObjectEnd = beatmap.HitObjects.Count > 0 ? beatmap.GetLastObjectTime() : 0;
 
             beginRampTime = firstObjectStart;

osu.Game/Tests/Visual/OnlinePlay/TestRoomRequestsHandler.cs

@@ -11,7 +11,6 @@
 using osu.Game.Online.Rooms;
 using osu.Game.Rulesets;
 using osu.Game.Tests.Beatmaps;
-using osu.Game.Tests.Visual;
 
 namespace osu.Game.Tests.Visual.OnlinePlay
 {