Fixed null reference caused by accessing property.objectReferenceValue. We don't need to record it as we should call ApplyModifiedProperties on serializedObject.

com.unity.render-pipelines.core/CoreRP/Editor/CoreEditorUtils.cs

 
             mode = EditorGUILayout.Popup(label, mode, options);
             if (EditorGUI.EndChangeCheck())
-            {
-                Undo.RecordObject(property.objectReferenceValue, property.name);
-            }
         }
 
         public static void DrawCascadeSplitGUI<T>(ref SerializedProperty shadowCascadeSplit)