[build.yaml] Scale down batch-driver before deleting instances (#11896)
[build.yaml] Scale down batch-driver before deleting instances (#11896)


hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail