Add changelog

Author: xrmx

Diff for: CHANGELOG.md

@@ -39,6 +39,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#2871](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2871))
 - `opentelemetry-instrumentation` Don't fail distro loading if instrumentor raises ImportError, instead skip them
   ([#2923](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2923))
+- `opentelemetry-instrumentation-httpx` Rewrote instrumentation to use wrapt instead of subclassing
+  ([#2909](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2909))
 
 ## Version 1.27.0/0.48b0 (2024-08-28)