editorconfig: Set default encoding to UTF-8 (#5793)

* editorconfig: Add default charset

* Change file encoding from UTF-8-BOM to UTF-8

src/Ryujinx.Ava/Input/AvaloniaKeyboard.cs

@@ -1,4 +1,4 @@
-using Ryujinx.Common.Configuration.Hid;
+using Ryujinx.Common.Configuration.Hid;
 using Ryujinx.Common.Configuration.Hid.Keyboard;
 using Ryujinx.Input;
 using System;

src/Ryujinx.Ava/Input/AvaloniaKeyboardDriver.cs

@@ -1,4 +1,4 @@
-using Avalonia.Controls;
+using Avalonia.Controls;
 using Avalonia.Input;
 using Ryujinx.Ava.Common.Locale;
 using Ryujinx.Input;

src/Ryujinx.Ava/Input/AvaloniaKeyboardMappingHelper.cs

@@ -1,4 +1,4 @@
-using Ryujinx.Input;
+using Ryujinx.Input;
 using System;
 using System.Collections.Generic;
 using AvaKey = Avalonia.Input.Key;