Revert "chore: update change log for Agent V3 N1C support. (#749)"

This reverts commit ba6b6f7.

Author: mjang

content/nginx-one/changelog.md

@@ -30,14 +30,6 @@ h2 {
 
 Stay up-to-date with what's new and improved in the F5 NGINX One Console.
 
-## June 30, 2025
-
-### NGINX Agent version 3 support
-
-We have added support for NGINX Agent 3.x in NGINX One Console. You can now:
-
-- Manage data plane instances with NGINX Agent version 3.
-
 ## May 19, 2025
 
 ### Import and export your Staged Configs