Update changelog for 16.3.4

GitLab Release Tools Bot · GitLab Release Tools Bot · commit 0d53c3d3a62f · 2023-09-18T14:02:52.000Z
[ci skip]
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -3,6 +3,10 @@
 The latest version of this file can be found at the master branch of the
 omnibus-gitlab repository.
 
+## 16.3.4 (2023-09-18)
+
+No changes.
+
 ## 16.3.3 (2023-09-12)
 
 No changes.
