Upload signed tarballs to GitHub Release

Author: sgilmore10

dev/release/02-source.sh

@@ -89,6 +89,9 @@ if [ ${SOURCE_UPLOAD} -gt 0 ]; then
   ${sha256_generate} $tarball > ${tarball}.sha256
   ${sha512_generate} $tarball > ${tarball}.sha512
 
+  # Upload signed tarballs to GitHub Release
+  gh release upload ${tag} ${tarball}.sha256 ${tarball}.sha512
+
   # check out the arrow RC folder
   svn co --depth=empty https://dist.apache.org/repos/dist/dev/arrow tmp