chore: bump version to 2.0.8

update changelog to 2.0.8

Author: wjyrich

debian/changelog

@@ -1,3 +1,9 @@
+dde-tray-loader (2.0.8) unstable; urgency=medium
+
+  * Release 2.0.8
+
+ -- wujiangyu <[email protected]>  Tue, 12 Aug 2025 10:39:30 +0800
+
 dde-tray-loader (2.0.7) unstable; urgency=medium
 
   * feat: improve battery icon loading strategy