Help/About: Run image comparison script after all assets have loaded.

If the callback is called before the images are loaded, the comparison doesn't work. `wp.domReady` uses `DOMContentLoaded`, which does not guarantee that the images are loaded. This switches to use the `load` event, which waits for all resources to load.

Props vladytimy, joyously, sergeybiryukov.
Fixes #52758.



git-svn-id: https://develop.svn.wordpress.org/trunk@50535 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/about.php

@@ -239,7 +239,7 @@ require_once ABSPATH . 'wp-admin/admin-header.php';
 <?php require_once ABSPATH . 'wp-admin/admin-footer.php'; ?>
 
 <script>
-	wp.domReady( function() {
+	window.addEventListener( 'load', function() {
 		var createElement = wp.element.createElement;
 		var Fragment = wp.element.Fragment;
 		var render = wp.element.render;