rev package:appengine to 0.13.9 for publishing (#177)

README.md

@@ -7,6 +7,7 @@ This repository is home to various Dart packages under the
 
 | Package | Description | Version |
 |---|---|---|
+| [appengine](pkgs/appengine/) | Support for using Dart as a custom runtime on Google App Engine Flexible Environment. | [![pub package](https://img.shields.io/pub/v/appengine.svg)](https://pub.dev/packages/appengine) |
 | [gcloud](pkgs/gcloud/) | High level idiomatic Dart API for Google Cloud Storage, Pub-Sub and Datastore. | [![pub package](https://img.shields.io/pub/v/gcloud.svg)](https://pub.dev/packages/gcloud) |
 | [native_synchronization](pkgs/native_synchronization/) | Low level synchronization primitives built on dart:ffi. | [![pub package](https://img.shields.io/pub/v/native_synchronization.svg)](https://pub.dev/packages/native_synchronization) |
 

pkgs/appengine/CHANGELOG.md

@@ -1,4 +1,4 @@
-## 0.13.9-wip
+## 0.13.9
 
 * Update the pubspec repository field to reflect the new repo location.
 

pkgs/appengine/pubspec.yaml

@@ -1,8 +1,8 @@
 name: appengine
-version: 0.13.9-wip
-description: >
+version: 0.13.9
+description: >-
   Support for using Dart as a custom runtime on Google App Engine Flexible
-  Environment
+  Environment.
 repository: https://github.com/dart-lang/labs/tree/main/pkgs/appengine
 
 topics: