unpack dl firmware artifacts in root

Author: Jason2866

.github/workflows/parallel_build.yaml

@@ -63,7 +63,7 @@ jobs:
     - name: Download build artifacts
       uses: actions/download-artifact@v4
       with:
-        path: dist
+        path: .
         pattern: artifacts-*
         merge-multiple: true
     - name: Download slave firmware