Update CHANGELOG.md for 12.7.4

[ci skip]

CHANGELOG.md

@@ -2,6 +2,13 @@
 documentation](doc/development/changelog.md) for instructions on adding your own
 entry.
 
+## 12.7.4
+
+### Security (1 change)
+
+- Update workhorse to v8.20.0.
+
+
 ## 12.7.3
 
 ### Security (17 changes, 1 of them is from the community)

changelogs/unreleased/a-signing-workhorse.yml

----
-title: Update workhorse to v8.20.0
-merge_request:
-author:
-type: security