Update CHANGELOG.md with bug fix entry

Co-authored-by: rujche <171773178+rujche@users.noreply.github.com>

Author: Copilot

sdk/spring/CHANGELOG.md

@@ -29,6 +29,7 @@ This section includes changes in `spring-cloud-azure-appconfiguration-config` mo
 #### Bugs Fixed
 
 - Fixed bug where `spring.cloud.azure.appconfiguration.enabled=false` was ignored in the new major version. [#47029](https://github.com/Azure/azure-sdk-for-java/pull/47029)
+- Fixed bug where connection string validation occurred even when `spring.cloud.azure.appconfiguration.enabled` is `false`.
 
 ### Azure Spring Data Cosmos
 This section includes changes in `azure-spring-data-cosmos` module.