update changelog

Author: xiang17

CHANGELOG.md

@@ -6,8 +6,6 @@
 
 * Run tests against Java 25
   ([#4495](https://github.com/microsoft/ApplicationInsights-Java/pull/4495), [#4494](https://github.com/microsoft/ApplicationInsights-Java/pull/4494))
-* Update gradle toolchain to Java 21
-  ([#4519](https://github.com/microsoft/ApplicationInsights-Java/pull/4519))
 
 ## Version 3.7.5 GA (09/25/2025)