Update parameter discards

osu.Game.Tests/Visual/Multiplayer/MultiplayerGameplayLeaderboardTestScene.cs

@@ -57,7 +57,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             // To emulate `MultiplayerClient.CurrentMatchPlayingUserIds` we need a bindable list of *only IDs*.
             // This tracks the list of users 1:1.
-            MultiplayerUsers.BindCollectionChanged((c, e) =>
+            MultiplayerUsers.BindCollectionChanged((_, e) =>
             {
                 switch (e.Action)
                 {

osu.Game.Tests/Visual/Multiplayer/TestSceneDrawableLoungeRoom.cs

@@ -42,7 +42,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             var mockLounge = new Mock<LoungeSubScreen>();
             mockLounge
                 .Setup(l => l.Join(It.IsAny<Room>(), It.IsAny<string>(), It.IsAny<Action<Room>>(), It.IsAny<Action<string>>()))
-                .Callback<Room, string, Action<Room>, Action<string>>((a, b, c, d) =>
+                .Callback<Room, string, Action<Room>, Action<string>>((_, _, _, d) =>
                 {
                     Task.Run(() =>
                     {

osu.Game.Tests/Visual/Multiplayer/TestSceneMatchStartControl.cs

@@ -90,7 +90,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
                                          setRoomCountdown(countdownStart.Duration);
                                          break;
 
-                                     case StopCountdownRequest _:
+                                     case StopCountdownRequest:
                                          multiplayerRoom.Countdown = null;
                                          raiseRoomUpdated();
                                          break;