Don't forget the github.com host name in the link

flatpak/bump-flatpak-version.py

@@ -92,7 +92,7 @@ def add_release_to_metainfo(
             desc_elem.append(child)
 
     url_elem = ET.SubElement(new_release, 'url')
-    url_elem.text = f'https://{repo}/releases/tag/{version}'
+    url_elem.text = f'https://github.com/{repo}/releases/tag/{version}'
 
     releases.insert(0, new_release)
     ET.indent(tree, space="    ", level=0)

flatpak/de.wger.flutter.metainfo.xml

@@ -82,7 +82,7 @@
             <description>
                 <p>Bug fixes and improvements.</p>
             </description>
-            <url>https://wger-project/flutter/releases/tag/1.8.3</url>
+            <url>https://github.com/wger-project/flutter/releases/tag/1.8.3</url>
         </release>
         <release version="1.5.3" date="2023-03-16" />
     </releases>