add changelog entry

Author: pmeier

CHANGELOG.md

@@ -37,6 +37,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#3589](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/3589))
 - opentelemetry-instrumentation: allow to skip all instrumentations loading with a wildcard
   ([#3967](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/3967))
+- `opentelemetry-instrumentation-redis`: add missing copyright header for opentelemetry-instrumentation-redis
+  ([#3976](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/3976))
 
 ### Fixed