Update changelog for 17.7.3

[ci skip]

CHANGELOG.md

@@ -3,6 +3,10 @@
 The latest version of this file can be found at the master branch of the
 omnibus-gitlab repository.
+## 17.7.3 (2025-01-22)
+
+No changes.
+
 ## 17.7.2 (2025-01-15)
 No changes.