fix(ci): pass version via env, use cat heredoc for changelog

.forgejo/workflows/build.yml

@@ -49,10 +49,18 @@ jobs:
 
       - name: Update debian changelog
         working-directory: /workspace/repo
+        env:
+          VERSION: ${{ steps.version.outputs.version }}
+          GIT_SHA: ${{ github.sha }}
         run: |
-          VERSION=${{ steps.version.outputs.version }}
           DATE=$(date -R)
-          printf '%s\n' "full-updater (${VERSION}) unstable; urgency=medium" "" "  * Auto-built release from commit ${GITHUB_SHA}" "" " -- Forgejo CI <ci@geronzi.fr>  ${DATE}" > debian/changelog
+          cat > debian/changelog << 'CHANGELOG'
+full-updater (${VERSION}) unstable; urgency=medium
+
+  * Auto-built release from commit ${GIT_SHA}
+
+ -- Forgejo CI <ci@geronzi.fr>  ${DATE}
+CHANGELOG
 
       - name: Install build dependencies
         working-directory: /workspace/repo