add changelog

Author: MikeGoldsmith

CHANGELOG.md

@@ -32,6 +32,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#4862](https://github.com/open-telemetry/opentelemetry-python/pull/4862))
 - `opentelemetry-exporter-otlp-proto-http`: fix retry logic and error handling for connection failures in trace, metric, and log exporters
   ([#4709](https://github.com/open-telemetry/opentelemetry-python/pull/4709))
+- `opentelemetry-sdk`: automatically generate configuration models using OTel config JSON schema
+  ([#4879](https://github.com/open-telemetry/opentelemetry-python/pull/4879))
 
 ## Version 1.39.0/0.60b0 (2025-12-03)