Add blog to release series yaml

Signed-off-by: Chris Cranford <chris@hibernate.org>

Author: Naros

_data/releases/3.4/3.4.0.Final.yml

@@ -2,4 +2,4 @@ date: 2025-12-18
 version: "3.4.0.Final"
 stable: true
 summary: Informix connector no support no-lock snapshot mode; PostgreSQL connector provides multiple strategies to handle flush LSN/LSN in offsets discrpeancy
-# announcement_url:
+announcement_url: /blog/2025/12/16/debezium-3-4-final-released/