Remove the item association property in the web application (#45425)

Author: laoneo

libraries/src/Application/WebApplication.php

@@ -56,16 +56,6 @@ abstract class WebApplication extends AbstractWebApplication
      */
     public $JComponentTitle;
 
-    /**
-     * The item associations
-     *
-     * @var    integer
-     * @since  4.3.0
-     *
-     * @deprecated 4.4.0 will be removed in 6.0 as this property is not used anymore
-     */
-    public $item_associations;
-
     /**
      * The application document object.
      *