Prepare release v9.2.1

Remove (unreleased) marker from v9.2.1 in CHANGELOG.md

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: RonnyPfannschmidt

CHANGELOG.md

@@ -1,7 +1,7 @@
 # Changelog
 
 
-## v9.2.1 (unreleased)
+## v9.2.1
 
 ### Fixed