Filesystem API: Update WP_Filesystem_FTPext::$link phpdoc type.

This accounts for when `ftp_ssl_connect()`/`ftp_connect()` returns `false` as well as for when `FTP\Connection` is returned instead of `resource` as of PHP 8.1. 

Props SirLouen, kalpeshh, audrasjb.
Fixes #63201.

Built from https://develop.svn.wordpress.org/trunk@61116


git-svn-id: http://core.svn.wordpress.org/trunk@60452 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/includes/class-wp-filesystem-ftpext.php

@@ -17,7 +17,7 @@ class WP_Filesystem_FTPext extends WP_Filesystem_Base {
 
 	/**
 	 * @since 2.5.0
-	 * @var resource
+	 * @var FTP\Connection|resource|false
 	 */
 	public $link;
 

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.9-beta2-61115';
+$wp_version = '6.9-beta2-61116';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.