add changelog.

Author: lukeina2z

CHANGELOG.md

@@ -12,3 +12,7 @@ For any change that affects end users of this package, please add an entry under
 If your change does not need a CHANGELOG entry, add the "skip changelog" label to your PR.
 
 ## Unreleased
+
+- fix: Remove Netty as an agent dependency
+  ([#1206](https://github.com/aws-observability/aws-otel-java-instrumentation/pull/1206))
+