Site Health: Correct `wp_version_check()` existence verification by performing a request to the Site Health page instead of Dashboard.

Props Clorith, audrasjb.
Fixes #46616.

git-svn-id: https://develop.svn.wordpress.org/trunk@45049 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/class-wp-site-health-auto-updates.php

@@ -101,7 +101,7 @@ class WP_Site_Health_Auto_Updates {
 			array(
 				'health-check-test-wp_version_check' => true,
 			),
-			admin_url()
+			admin_url( 'site-health.php' )
 		);
 
 		$test = wp_remote_get( $url, compact( 'cookies', 'headers', 'timeout' ) );

src/wp-admin/includes/class-wp-site-health.php

@@ -28,8 +28,6 @@ class WP_Site_Health {
 	public function __construct() {
 		$this->prepare_sql_data();
 
-		add_action( 'wp_loaded', array( $this, 'check_wp_version_check_exists' ) );
-
 		add_filter( 'admin_body_class', array( $this, 'admin_body_class' ) );
 
 		add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_scripts' ) );

src/wp-admin/site-health.php

@@ -27,6 +27,9 @@ if ( ! class_exists( 'WP_Site_Health' ) ) {
 
 $health_check_site_status = new WP_Site_Health();
 
+// Start by checking if this is a special request checking for the existence of certain filters.
+$health_check_site_status->check_wp_version_check_exists();
+
 require_once( ABSPATH . 'wp-admin/admin-header.php' );
 ?>