Move StreamGroup.broadcast() fix to 2.14.0-wip section

Author: suojae

pkgs/async/CHANGELOG.md

@@ -1,7 +1,10 @@
+## 2.13.1-wip
+
+- Fix `StreamGroup.broadcast().close()` to properly complete when all streams in the group close without being explicitly removed.
+
 ## 2.13.0
 
 - Fix type check and cast in SubscriptionStream's cancelOnError wrapper
-- Fix `StreamGroup.broadcast().close()` to properly complete when all streams in the group close without being explicitly removed.
 
 ## 2.12.0