Move pr1428 changelog entry from 0.3.8 to unreleased (#1433)

* move breaking changes from 0.3.8 to unreleased

* force PR build

Author: BryanJY-Wong

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Breaking Changes
+
+- The `GetResponse<T>(CommandRequestId)` method in the `IDiffCommandResponseStorage` and `CommandSystem` now returns a `T?` instead of `MessageSpan<T>` [#1428](https://github.com/spatialos/gdk-for-unity/pull/1428)
+
 ### Added
 
 - Added support for multiple annotations in Code Writer API. [#1427](https://github.com/spatialos/gdk-for-unity/pull/1427)
@@ -22,7 +26,6 @@
     - See the [upgrade guide](UPGRADE_GUIDE.md) for detailed upgrade instructions for this breaking change.
     - `IEntityGameObjectCreator.PopulateEntityTypeExpectations` now only needs to specify what SpatialOS components it needs for spawning an entity, such as `Position`.
     - `GameObjectCreationHelper.EnableStandardGameObjectCreation` now requires a non-null `EntityRepresentationMapping` to be passed in.
-- The `GetResponse<T>(CommandRequestId)` method in the `IDiffCommandResponseStorage` and `CommandSystem` now returns a `T?` instead of `MessageSpan<T>` [#1428](https://github.com/spatialos/gdk-for-unity/pull/1428)
 
 ### Added