Use only generated changelog file.

The combination of the manually and auto generated parts failed the lint
check.

changelogs/changelog.yaml

@@ -1,13 +1,9 @@
 ancestor: null
 releases:
   1.0.0:
-    changes:
-      release_summary: Initial release
-    fragments:
-    - Initial release
     objects:
       role:
-      - description: Configure kernel-install to use UKIs
+      - description: UKI Configuration.
         name: uki_config
         namespace: null
     release_date: '2024-08-02'