v2.9.7-canary.8

<!-- Release notes generated using configuration in .github/release.yml at v2.9.7-canary.8 -->

What's Changed

Changelog

• fix: Preserve graceful shutdown exit code by @anthonyshew in https://github.com/vercel/turborepo/pull/12620

Full Changelog: https://github.com/vercel/turborepo/compare/v2.9.7-canary.7...v2.9.7-canary.8