changelog: add notes about closing #12489

[skip ci]

CHANGELOG.md

@@ -21,6 +21,7 @@
 * **Github OAuth**: Allow changes of user info at Github to be synched to Grafana when signing in [#11818](https://github.com/grafana/grafana/issues/11818), thx [@rwaweber](https://github.com/rwaweber)
 * **Alerting**: Fix diff and percent_diff reducers [#11563](https://github.com/grafana/grafana/issues/11563), thx [@jessetane](https://github.com/jessetane)
 * **Units**: Polish złoty currency [#12691](https://github.com/grafana/grafana/pull/12691), thx [@mwegrzynek](https://github.com/mwegrzynek)
+* **Cloudwatch**: Improved error handling [#12489](https://github.com/grafana/grafana/issues/12489), thx [@mtanda](https://github.com/mtanda)
 
 # 5.2.2 (unreleased)