GIT_SILENT Update Appstream for new release

(cherry picked from commit 6f2c6ab8)

org.kde.kcharselect.appdata.xml

@@ -244,9 +244,9 @@
   </provides>
   <launchable type="desktop-id">org.kde.kcharselect.desktop</launchable>
   <releases>
+    <release version="20.12.3" date="2021-03-04"/>
     <release version="20.12.2" date="2021-02-04"/>
     <release version="20.12.1" date="2021-01-07"/>
     <release version="20.12.0" date="2020-12-10"/>
-    <release version="20.08.3" date="2020-11-05"/>
   </releases>
 </component>