Fix CI generic math compile errors from missing System.Numerics imports

Agent-Logs-Url: https://github.com/winnerspiros/osu/sessions/e9d86dc5-3d43-412f-b41a-36c70f51a28f

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

Author: Copilot

osu.Game/Extensions/NumberFormattingExtensions.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Globalization;
+using System.Numerics;
 using osu.Game.Utils;
 
 namespace osu.Game.Extensions

osu.Game/Graphics/UserInterface/OsuSliderBar.cs

@@ -9,6 +9,7 @@
 using osu.Framework.Localisation;
 using osu.Framework.Utils;
 using osu.Game.Extensions;
+using System.Numerics;
 
 namespace osu.Game.Graphics.UserInterface
 {

osu.Game/Overlays/Settings/Sections/SizeSlider.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Globalization;
+using System.Numerics;
 using osu.Framework.Localisation;
 using osu.Game.Graphics.UserInterface;
 

osu.Game/Overlays/Settings/SettingsPercentageSlider.cs

@@ -4,6 +4,7 @@
 using osu.Framework.Graphics;
 using osu.Game.Configuration;
 using osu.Game.Graphics.UserInterface;
+using System.Numerics;
 
 namespace osu.Game.Overlays.Settings
 {

osu.Game/Overlays/Settings/SettingsSlider.cs

@@ -4,6 +4,7 @@
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.UserInterface;
 using osu.Game.Graphics.UserInterface;
+using System.Numerics;
 
 namespace osu.Game.Overlays.Settings
 {

osu.Game/Screens/Play/PlayerSettings/PlayerSliderBar.cs

@@ -6,6 +6,7 @@
 using osu.Game.Graphics;
 using osu.Game.Graphics.UserInterface;
 using osu.Game.Overlays.Settings;
+using System.Numerics;
 
 namespace osu.Game.Screens.Play.PlayerSettings
 {