Add PHPStan typing for return value of WP_Sync_Post_Meta_Storage::with_suspended_posts_last_changed_update()

Co-authored-by: gemini-cli <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: westonruter

src/wp-includes/collaboration/class-wp-sync-post-meta-storage.php

@@ -332,8 +332,9 @@ public function remove_updates_before_cursor( string $room, int $cursor ): bool
 	 * @since 7.0.0
 	 * @see wp_cache_set_posts_last_changed()
 	 *
-	 * @param Closure $callback Callback
-	 * @return mixed Return value from the callback.
+	 * @template T
+	 * @param Closure(): T $callback Callback.
+	 * @return T Return value from the callback.
 	 */
 	private function with_suspended_posts_last_changed_update( Closure $callback ) {
 		$priorities = array(