Refs #31483 -- Removed CSS and JavaScript for unused HTML class add-another.

The HTML class was removed in 07988744b3.
As such, the CSS and JavaScript is unused.

django/contrib/admin/static/admin/css/forms.css

@@ -501,7 +501,7 @@ body.popup .submit-row {
 
 /* RELATED FIELD ADD ONE / LOOKUP */
 
-.add-another, .related-lookup {
+.related-lookup {
     margin-left: 5px;
     display: inline-block;
     vertical-align: middle;
@@ -509,12 +509,6 @@ body.popup .submit-row {
     background-size: 14px;
 }
 
-.add-another {
-    width: 16px;
-    height: 16px;
-    background-image: url(../img/icon-addlink.svg);
-}
-
 .related-lookup {
     width: 16px;
     height: 16px;

django/contrib/admin/static/admin/css/responsive.css

@@ -226,7 +226,6 @@ input[type="submit"], button {
         padding-top: 6px;
     }
 
-    .aligned .add-another,
     .aligned .related-lookup,
     .aligned .datetimeshortcuts,
     .aligned .related-lookup + strong {

django/contrib/admin/static/admin/css/responsive_rtl.css

@@ -71,7 +71,6 @@
         margin-left: 0;
     }
 
-    [dir="rtl"] .aligned .add-another,
     [dir="rtl"] .aligned .related-lookup,
     [dir="rtl"] .aligned .datetimeshortcuts {
         margin-left: 0;

django/contrib/admin/static/admin/js/change_form.js

@@ -1,18 +1,7 @@
-/*global showAddAnotherPopup, showRelatedObjectLookupPopup showRelatedObjectPopup updateRelatedObjectLinks*/
-
 (function($) {
     'use strict';
     $(document).ready(function() {
         var modelName = $('#django-admin-form-add-constants').data('modelName');
-        $('body').on('click', '.add-another', function(e) {
-            e.preventDefault();
-            var event = $.Event('django:add-another-related');
-            $(this).trigger(event);
-            if (!event.isDefaultPrevented()) {
-                showAddAnotherPopup(this);
-            }
-        });
-
         if (modelName) {
             $('form#' + modelName + '_form :input:visible:enabled:first').focus();
         }