Update dates

Author: Amar3tto

CHANGES.md

@@ -97,7 +97,7 @@
 
 * ([#X](https://github.com/apache/beam/issues/X)).
 
-# [2.68.0] - 2025-09-??
+# [2.68.0] - 2025-09-23
 
 ## Highlights
 

website/www/site/content/en/blog/beam-2.68.0.md

@@ -1,6 +1,6 @@
 ---
 title:  "Apache Beam 2.68.0"
-date:   2025-09-?? 15:00:00 -0500
+date:   2025-09-23 15:00:00 -0500
 categories:
   - blog
   - release