build(deps-dev): bump turbo from 2.8.21 to 2.9.4 in /website (#4924)

Bumps [turbo](https://github.com/vercel/turborepo) from 2.8.21 to 2.9.4.
- [Release notes](https://github.com/vercel/turborepo/releases)
- [Changelog](https://github.com/vercel/turborepo/blob/main/RELEASE.md)
- [Commits](https://github.com/vercel/turborepo/compare/v2.8.21...v2.9.4)

---
updated-dependencies:
- dependency-name: turbo
  dependency-version: 2.9.4
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Fleny <Fleny113@outlook.com>

website/package.json

@@ -36,7 +36,7 @@
     "@docusaurus/tsconfig": "^3.9.2",
     "@docusaurus/types": "^3.9.2",
     "@types/react": "^19.2.14",
-    "turbo": "^2.8.21",
+    "turbo": "^2.9.4",
     "typescript": "6.0.2",
     "webpack": "5.105.4"
   },