Add a changelog entry

For eng/ide/ada_language_server#1581

Author: eliericha

CHANGELOG.md

@@ -5,6 +5,7 @@ section below it for the last release. -->
 ## \<next>
 
 * Support single-line (`//`) and multi-line (`/* */`) comments in ALS JSON configuration files
+* Fix the reporting of test results in the Testing view when the test tree is not expanded
 
 ## 26.0.202412190