docs(Client): mark _finalize as private (#6281)

src/client/Client.js

@@ -366,6 +366,7 @@ class Client extends BaseClient {
    * @param {Function} options.cleanup The function called to GC
    * @param {string} [options.message] The message to send after a successful GC
    * @param {string} [options.name] The name of the item being GCed
+   * @private
    */
   _finalize({ cleanup, message, name }) {
     try {