Copy changelog updates from package-release/opentelemetry-instrumentation-openai-v2/v2.1bx (#3197)

Co-authored-by: Riccardo Magliocchetti <[email protected]>

Author: opentelemetrybot

instrumentation-genai/opentelemetry-instrumentation-openai-v2/CHANGELOG.md

@@ -7,7 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
-## Version 2.1b0 (2025-01-17)
+## Version 2.1b0 (2025-01-18)
 
 - Coerce openai response_format to semconv format
   ([#3073](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/3073))