Update CHANGELOG.md for 12.3.1

[ci skip]

CHANGELOG.md

@@ -2,6 +2,16 @@
 documentation](doc/development/changelog.md) for instructions on adding your own
 entry.
 
+## 12.3.1
+
+### Fixed (4 changes)
+
+- Fix ordering of issue board lists not being persisted. !17356
+- Fix error when duplicate users are merged in approvers list. !17406
+- Fix bug that caused a merge to show an error message. !17466
+- Fix CSS leak in job log.
+
+
 ## 12.3.0
 
 ### Security (23 changes)

changelogs/unreleased/32408-fix-css-leak.yml

----
-title: Fix CSS leak in job log
-merge_request:
-author:
-type: fixed

changelogs/unreleased/32427-cannot-reorder-issue-boards.yml

----
-title: Fix ordering of issue board lists not being persisted
-merge_request: 17356
-author:
-type: fixed

changelogs/unreleased/sh-fix-any-approver-handling.yml

----
-title: Fix bug that caused a merge to show an error message
-merge_request: 17466
-author:
-type: fixed

changelogs/unreleased/sh-fix-dupe-approvals-failing.yml

----
-title: Fix error when duplicate users are merged in approvers list
-merge_request: 17406
-author:
-type: fixed