v2.8.21-canary.16

<!-- Release notes generated using configuration in .github/release.yml at v2.8.21-canary.16 -->

What's Changed

Changelog

• docs: Add missing --force flag documentation by @Goldyvaiiii in https://github.com/vercel/turborepo/pull/12440
• fix: Prevent panic in turbo watch with persistent tasks by @anthonyshew in https://github.com/vercel/turborepo/pull/12459

Full Changelog: https://github.com/vercel/turborepo/compare/v2.8.21-canary.15...v2.8.21-canary.16