v2.8.15-canary.2

<!-- Release notes generated using configuration in .github/release.yml at v2.8.15-canary.2 -->

What's Changed

Changelog

• perf: Defer SCM task await to overlap with setup work by @anthonyshew in https://github.com/vercel/turborepo/pull/12177

Full Changelog: https://github.com/vercel/turborepo/compare/v2.8.15-canary.1...v2.8.15-canary.2