ci: update source download script (#10)

Co-authored-by: Averi Kitsch <akitsch@google.com>

Author: duwenxin99

.github/workflows/package-and-upload-assets.yml

@@ -66,6 +66,7 @@ jobs:
           
           echo "Downloading binary from: ${DOWNLOAD_URL}"
           curl -L --fail -o "${SOURCE_BINARY}" "${DOWNLOAD_URL}"
+          chmod +x ${SOURCE_BINARY}
           
           echo "Binary downloaded and prepared."
           ls -l