ISTWCMS-4803: Removing dependency from mathjax ckeditor plugin.

src/Plugin/CKEditorPlugin/MathJaxPlugin.php

@@ -57,7 +57,6 @@ class MathJaxPlugin extends CKEditorPluginBase implements ContainerFactoryPlugin
       'clipboard',
       'dialog',
       'lineutils',
-      'widget',
     ];
   }