Fix a bug KeyEvent declared twice. due to rebase problems.

Terminal.Gui/Core.cs

@@ -1070,11 +1070,6 @@ namespace Terminal.Gui {
 			public KeyEvent KeyEvent { get; set; }
 		}
 
-		public class KeyEventEventArgs : EventArgs {
-			public KeyEventEventArgs(KeyEvent ke) => KeyEvent = ke;
-			public KeyEvent KeyEvent { get; set; }
-		}
-
 		/// <summary>
 		/// Invoked when a character key is pressed and occurs after the key up event.
 		/// </summary>