v2.8.21-canary.6

<!-- Release notes generated using configuration in .github/release.yml at v2.8.21-canary.6 -->

What's Changed

Changelog

• docs: Promote turbo query from experimental to stable by @anthonyshew in https://github.com/vercel/turborepo/pull/12421
• docs: Clarify turbo-ignore's future by @anthonyshew in https://github.com/vercel/turborepo/pull/12422

Full Changelog: https://github.com/vercel/turborepo/compare/v2.8.21-canary.5...v2.8.21-canary.6