Add changelog entry about open-telemetry#3673

Author: andremm

CHANGELOG.md

@@ -11,6 +11,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+### Fixed
+
+- `opentelemetry-instrumentation`: Avoid calls to `context.detach` with `None` token.
+  ([#3673](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/3673))
+
 ## Version 1.36.0/0.57b0 (2025-07-29)
 
 ### Fixed