in this series, we do not assume the existence of "build" build directory. and prefer using the version files located under the directory specified with the `--build-dir` option. Refs #15241 Closes scylladb/scylladb#15402 * github.com:scylladb/scylladb: create-relocatable-package.py: prefer $build_dir/SCYLLA-RELEASE-FILE create-relocatable-package.py: create SCYLLA-RELOCATABLE-FILE with tempfile