Admin: Use `is_user_logged_in()` instead of `wp_validate_auth_cookie()` in `admin-post.php`.

This matches the authentication check in `admin-ajax.php`, and allows the authentication method to be filtered.

Props jmdodd.
Fixes #45475.


Built from https://develop.svn.wordpress.org/trunk@44615


git-svn-id: http://core.svn.wordpress.org/trunk@44446 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/admin-post.php

@@ -31,7 +31,7 @@ do_action( 'admin_init' );
 
 $action = empty( $_REQUEST['action'] ) ? '' : $_REQUEST['action'];
 
-if ( ! wp_validate_auth_cookie() ) {
+if ( ! is_user_logged_in() ) {
 	if ( empty( $action ) ) {
 		/**
 		 * Fires on a non-authenticated admin post request where no action is supplied.

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.1-beta1-44614';
+$wp_version = '5.1-beta1-44615';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.