Add @static* annotations where they are missing.

Initialize all static vars that are not, most to `null`.

See #32444.


git-svn-id: https://develop.svn.wordpress.org/trunk@32650 602fd350-edb4-49c9-b593-d223f7449a82

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

@@ -1658,6 +1658,8 @@ class Language_Pack_Upgrader extends WP_Upgrader {
 	 * Hooked to the {@see 'upgrader_process_complete'} action by default.
 	 *
 	 * @since 3.7.0
+	 *
+	 * @static
 	 */
 	public static function async_upgrade( $upgrader = false ) {
 		// Avoid recursion.
@@ -2136,6 +2138,8 @@ class Core_Upgrader extends WP_Upgrader {
 	 *
 	 * @since 3.7.0
 	 *
+	 * @static
+	 *
 	 * @param string $offered_ver The offered version, of the format x.y.z.
 	 * @return bool True if we should update to the offered version, otherwise false.
 	 */