CI: remove directories from dist dir before upload step (#6429)

.github/workflows/release.yaml

@@ -474,6 +474,7 @@ jobs:
           ls -lh dist/
           (cd dist; find . -type f | xargs sha256sum > ../sha256sum.txt)
           mv sha256sum.txt dist/
+          mv dist/linux-???64 .
           cat dist/sha256sum.txt
       - name: Create or update Release
         run: |