Update CHANGELOG-EE.md for 12.2.4-ee

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CHANGELOG-EE.md

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+## 12.2.4
+
+### Fixed (1 change)
+
+- Fix group hooks not firing in PostReceive. !15598
+
+
 ## 12.2.3
 ### Security (2 changes)

ee/changelogs/unreleased/sh-fix-group-hooks.yml

----
-title: Fix group hooks not firing in PostReceive
-merge_request: 15598
-author:
-type: fixed