Mark 129 as approved (#1245)

* Mark 129 as approved

* Add changelog, update time

* Remove extra bullet

Author: slevenick

aip/general/0129.md

@@ -1,7 +1,8 @@
 ---
 id: 129
-state: draft
+state: approved
 created: 2023-09-20
+updated: 2023-10-31
 placement:
   category: resource-design
   order: 65
@@ -134,11 +135,13 @@ semantically meaningful. When a [Declarative client][Declarative clients]
 sends a particular value it will ensure that the value is being returned by the
 service to validate it was set correctly.
 
+## Changelog
+
+- **2023-10-31:** Update to approved.
+
 [Declarative clients]: ./0009#declarative-clients
 [aip-202]: ./202.md
 
-- 
-
 <!-- prettier-ignore-start -->
 [aip-180]: ./0180.md
 [state-driven-clients]: ./009.md#state-driven-clients