Add changelog entry for disableUpdateNotifications setting

Co-authored-by: kylecarbs <7122116+kylecarbs@users.noreply.github.com>

Author: blink-so[bot]

CHANGELOG.md

@@ -4,6 +4,8 @@
 
 - Update `/openDevContainer` to support all dev container features when hostPath
   and configFile are provided.
+- Add `coder.disableUpdateNotifications` setting to disable workspace template
+  update notifications.
 
 ## [v1.9.2](https://github.com/coder/vscode-coder/releases/tag/v1.9.2) 2025-06-25