fix: remove old code in tabs, always set tabindex to 0 when tabs are initialized

Author: Daniel Ruf

lib/web/mage/tabs.js

@@ -83,25 +83,16 @@ define([
 
         /**
          * When the widget gets instantiated, the first tab that is not disabled receive focusable property
-         * Updated: for accessibility all tabs receive tabIndex 0
+         * All tabs receive tabIndex 0
          * @private
          */
         _processTabIndex: function () {
             var self = this;
 
             self.triggers.attr('tabIndex', 0);
             $.each(this.collapsibles, function (i) {
-                if (!$(this).collapsible('option', 'disabled')) {
-                    self.triggers.eq(i).attr('tabIndex', 0);
-
-                    return false;
-                }
-            });
-            $.each(this.collapsibles, function (i) {
-                $(this).on('beforeOpen', function () {
-                    self.triggers.attr('tabIndex', 0);
-                    self.triggers.eq(i).attr('tabIndex', 0);
-                });
+                self.triggers.attr('tabIndex', 0);
+                self.triggers.eq(i).attr('tabIndex', 0);
             });
         },