chore: update tsdown

[lachlancollins]

🎯 Changes

• v0.20.0 uses the rolldown rc.1

✅ Checklist

• I have followed the steps in the Contributing guide.
• I have tested this code locally with pnpm test:pr.

🚀 Release Impact

• This change affects published code, and I have generated a changeset.
• This change is docs/CI/dev-only (no release).

[changeset-bot]

⚠️ No Changeset found

Latest commit: fd63061

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

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[nx-cloud]

View your CI Pipeline Execution ↗ for commit fd63061

Command	Status	Duration	Result
nx affected --targets=test:sherif,test:docs,tes...	✅ Succeeded	26s	View ↗
nx run-many --target=build	✅ Succeeded	11s	View ↗

---

☁️ Nx Cloud last updated this comment at 2026-01-23 07:54:21 UTC

[pkg-pr-new]

npm i https://pkg.pr.new/@tanstack/eslint-config@332

npm i https://pkg.pr.new/@tanstack/publish-config@332

npm i https://pkg.pr.new/@tanstack/typedoc-config@332

npm i https://pkg.pr.new/@tanstack/vite-config@332

commit: fd63061