docs: update changelog for integrations/google_vertex (#2530)

* Update changelog for integrations/google_vertex

* Update CHANGELOG for integration migration

Archived google-ai and google-vertex integrations and migrated to google-genai.

---------

Co-authored-by: vblagoje <458335+vblagoje@users.noreply.github.com>
Co-authored-by: Vladimir Blagojevic <dovlex@gmail.com>

Author: HaystackBot

integrations/google_vertex/CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## [integrations/google_vertex-v5.3.0.post1] - 2025-11-18
+
+### 🧹 Chores
+
+- archive google-ai and google-vertex integrations, migrate to google-genai (#2521)
+
 ## [integrations/google_vertex-v5.3.0] - 2025-07-29
 
 ### 🐛 Bug Fixes