Add v5.11.0-beta.2 to CHANGELOG

(cherry picked from commit b26c6ce)

Author: kategengler

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Ember Changelog
 
+## v5.11.0-beta.2 (August 6, 2024)
+
+- [#20726](https://github.com/emberjs/ember.js/pull/20726) [BUGFIX] Fix test waiters by removing unintentional duplication from ember-testing bundle
+- [#20715](https://github.com/emberjs/ember.js/pull/20715) [BUGFIX] Don't publish empty modules
+
 ## v5.11.0-beta.1 (July 8, 2024)
 
 - [#20716](https://github.com/emberjs/ember.js/pull/20716) [BREAKING] Drop Node 16 support