Fixes parsing error in appdata
Index: siril/platform-specific/linux/org.siril.Siril.appdata.xml
===================================================================
--- siril.orig/platform-specific/linux/org.siril.Siril.appdata.xml
+++ siril/platform-specific/linux/org.siril.Siril.appdata.xml
@@ -145,7 +145,6 @@
       </description>
 
     </release>
-  <releases>
     <release version="1.4.0-beta1" date="2025-04-26">
       <url type="details">https://siril.org/download/1.4.0-beta1</url>
       <description>
