docs: moved changelog entry to unreleased

Author: Dudssource

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+- Fix `OTLPMetricExporter` ignores `preferred_aggregation` property
+  ([#3603](https://github.com/open-telemetry/opentelemetry-python/pull/3603))
 - Logs: set `observed_timestamp` field
   ([#3565](https://github.com/open-telemetry/opentelemetry-python/pull/3565))
 - Add missing Resource SchemaURL in OTLP exporters
@@ -50,7 +52,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   ([#3524](https://github.com/open-telemetry/opentelemetry-python/pull/3524))
 - Handle `taskName` `logrecord` attribute
   ([#3557](https://github.com/open-telemetry/opentelemetry-python/pull/3557))
-- Fix `OTLPMetricExporter` ignores `preferred_aggregation` property ([#3603](https://github.com/open-telemetry/opentelemetry-python/pull/3603))
 
 ## Version 1.21.0/0.42b0 (2023-11-01)