Docs: Add @access entry for Automatic_Upgrader_Skin::request_filesystem_credentials().

Props rushabh4486.
Fixes #41383.

git-svn-id: https://develop.svn.wordpress.org/trunk@41107 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/class-automatic-upgrader-skin.php

@@ -27,6 +27,7 @@ class Automatic_Upgrader_Skin extends WP_Upgrader_Skin {
 	 *
 	 * @since 3.7.0
 	 * @since 4.6.0 The `$context` parameter default changed from `false` to an empty string.
+	 * @access public
 	 *
 	 * @see request_filesystem_credentials()
 	 *