chore: update version to 6.6.28

- bump version to 6.6.28

Log : bump version to 6.6.28

Author: wyu71

debian/changelog

@@ -1,3 +1,9 @@
+deepin-screen-recorder (6.6.28) unstable; urgency=medium
+
+  * fix(record): delay app exit to ensure clipboard operation completes
+
+ -- Wang Yu <wangyu@uniontech.com>  Fri, 27 Mar 2026 18:03:56 +0800
+
 deepin-screen-recorder (6.6.27) unstable; urgency=medium
 
   * chroe: Modify translations