Increase App Engine timeout from 400s to 1000s (#2325)

* Increase App Engine timeout from 400s to 1000s

Fix failing deployments by increasing the App Engine timeout from 400s to 1000s in app.yaml.

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Co-Authored-By: Claude <[email protected]>

* Add versioning

---------

Co-authored-by: Claude <[email protected]>

Author: nikhilwoodruff

changelog_entry.yaml

@@ -0,0 +1,4 @@
+- bump: patch
+  changes:
+    changed:
+    - Deployment readiness check timeout to 1000s.

gcp/policyengine_api/app.yaml

@@ -21,4 +21,4 @@ runtime_config:
   runtime_version: "22"
 readiness_check:
   path: "/readiness_check"
-  app_start_timeout_sec: 400
+  app_start_timeout_sec: 1000