Maintenance: Update for Zammad 6.1.0.

CHANGELOG.md

@@ -1,7 +1,8 @@
 # Change Log
 
-## [5.5.0](https://github.com/zammad/zammad/tree/5.5.0) (2023-xx-xx)
-[Full Changelog](https://github.com/zammad/zammad/compare/5.4.0...5.5.0)
+## [6.1.0](https://github.com/zammad/zammad/tree/6.1.0) (2023-xx-xx)
+
+[Full Changelog](https://github.com/zammad/zammad/compare/6.0.0...6.1.0)
 
 **Implemented enhancements:**
 

SECURITY.md

@@ -4,8 +4,8 @@
 
 | Version  | Supported          |
 | -------- | ------------------ |
-| 5.4.x    | :white_check_mark: |
-| <= 5.3.x | :x:                |
+| 6.0.x    | :white_check_mark: |
+| <= 5.4.x | :x:                |
 
 ## Reporting a Vulnerability