Revert "Fixing Editor_CanIconsForLayouts() unit test"

This reverts commit a225669.

Author: josepmariapujol-unity

Assets/Tests/InputSystem/CoreTests_Editor.cs

@@ -22,7 +22,6 @@
 using UnityEngine.InputSystem.Processors;
 using UnityEngine.InputSystem.Users;
 using UnityEngine.InputSystem.Utilities;
-using UnityEngine.Rendering;
 using UnityEngine.TestTools;
 
 #pragma warning disable CS0649
@@ -2633,9 +2632,6 @@ public void Editor_CanListOptionalControlsForLayout()
     [Category("Editor")]
     public void Editor_CanIconsForLayouts()
     {
-        if (SystemInfo.graphicsDeviceType == GraphicsDeviceType.Null)
-            Assert.Ignore("Skipping icon test in headless/null graphics environment.");
-        
         const string kIconPath = "Packages/com.unity.inputsystem/Editor/Icons/";
         var skinPrefix = EditorGUIUtility.isProSkin ? "d_" : "";
         var scale = Mathf.Clamp((int)EditorGUIUtility.pixelsPerPoint, 0, 4);