v2.8.17-canary.9

<!-- Release notes generated using configuration in .github/release.yml at v2.8.17-canary.9 -->

What's Changed

Changelog

• feat: Send x-ai-agent header on all Vercel API requests by @anthonyshew in https://github.com/vercel/turborepo/pull/12261
• fix: Deflake watch_edit_during_build_triggers_rebuild test by @anthonyshew in https://github.com/vercel/turborepo/pull/12263

Full Changelog: https://github.com/vercel/turborepo/compare/v2.8.17-canary.8...v2.8.17-canary.9