Add CHANGELOG entry for CeleryGetter fix

Author: DrMeers

CHANGELOG.md

@@ -24,6 +24,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- `opentelemetry-instrumentation-celery`: Coerce non-string values to strings in `CeleryGetter.get()` to prevent `TypeError` in `TraceState.from_header()` when Celery request attributes contain ints
+  ([#4360](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/4360))
 - `opentelemetry-docker-tests`: Replace deprecated `SpanAttributes` from `opentelemetry.semconv.trace` with `opentelemetry.semconv._incubating.attributes`
  ([#4339](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/4339))
 - `opentelemetry-instrumentation-confluent-kafka`: Skip `recv` span creation when `poll()` returns no message or `consume()` returns an empty list, avoiding empty spans on idle polls