GIT_SILENT Update Appstream for new release

(cherry picked from commit c37a7a8b)

src/org.kde.kapman.appdata.xml

@@ -166,10 +166,10 @@
   </screenshots>
   <project_group>KDE</project_group>
   <releases>
+    <release version="21.12.3" date="2022-03-03"/>
     <release version="21.12.2" date="2022-02-03"/>
     <release version="21.12.1" date="2022-01-06"/>
     <release version="21.12.0" date="2021-12-09"/>
-    <release version="21.08.3" date="2021-11-04"/>
   </releases>
   <content_rating type="oars-1.1">
     <content_attribute id="violence-cartoon">mild</content_attribute>