Add changelog

Author: DylanRussell

CHANGELOG.md

@@ -16,6 +16,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#4755](https://github.com/open-telemetry/opentelemetry-python/pull/4755))
 - logs: extend Logger.emit to accept separated keyword arguments
   ([#4737](https://github.com/open-telemetry/opentelemetry-python/pull/4737))
+- Add `opentelemetry-exporter-credential-provider-gcp` as an optional dependency to `opentelemetry-exporter-otlp-proto-grpc` 
+  and `opentelemetry-exporter-otlp-proto-http` ([#4760](https://github.com/open-telemetry/opentelemetry-python/pull/4760)).
 
 ## Version 1.37.0/0.58b0 (2025-09-11)