Fix build workflow: split Save image artifact into two steps

- Separate docker save command from upload-artifact action
- Fix invalid syntax error (cannot use both uses: and run: in same step)
- Steps now properly separated: Save image to file, then Upload image artifact

.gitea/workflows/build.yml

@@ -109,13 +109,16 @@ jobs:
           echo "${{ secrets.REGISTRY_PASSWORD }}" | docker login ${{ env.REGISTRY }} -u "${{ secrets.REGISTRY_USERNAME }}" --password-stdin
           docker push "${{ steps.image.outputs.full }}"
 
-      - name: Save image artifact
+      - name: Save image to file
+        if: env.REGISTRY == ''
+        run: |
+          docker save "${IMAGE_NAME}:${IMAGE_TAG}" -o /tmp/image.tar
+
+      - name: Upload image artifact
+        if: env.REGISTRY == ''
         uses: actions/upload-artifact@v4
         with:
           name: docker-image
           path: /tmp/image.tar
           retention-days: 1
-        if: env.REGISTRY == ''
-        run: |
-          docker save "${IMAGE_NAME}:${IMAGE_TAG}" -o /tmp/image.tar