v2.8.21-canary.20

<!-- Release notes generated using configuration in .github/release.yml at v2.8.21-canary.20 -->

What's Changed

Changelog

• fix: Remove root package.json from --affected global triggers by @anthonyshew in https://github.com/vercel/turborepo/pull/12469

Full Changelog: https://github.com/vercel/turborepo/compare/v2.8.21-canary.19...v2.8.21-canary.20