add changelog

Author: samuelcolvin

CHANGELOG.md

@@ -10,7 +10,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 - `opentelemetry-instrumentation-celery` Allow Celery instrumentation to be installed multiple times
   ([#2342](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2342))
-- Align gRPC span status codes to OTEL specification ([#1756](https://github.com/open-telemetry/opentelemetry-python-contrib/issues/1756))
+- Align gRPC span status codes to OTEL specification
+  ([#1756](https://github.com/open-telemetry/opentelemetry-python-contrib/issues/1756))
+- Avoid losing repeated HTTP headers
+  ([#2266](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/2266))
 
 ## Version 1.23.0/0.44b0 (2024-02-23)