Bump @astrojs/vercel from 8.2.8 to 9.0.0

Bumps [@astrojs/vercel](https://github.com/withastro/astro/tree/HEAD/packages/integrations/vercel) from 8.2.8 to 9.0.0.
- [Release notes](https://github.com/withastro/astro/releases)
- [Changelog](https://github.com/withastro/astro/blob/main/packages/integrations/vercel/CHANGELOG.md)
- [Commits](https://github.com/withastro/astro/commits/HEAD/packages/integrations/vercel)

---
updated-dependencies:
- dependency-name: "@astrojs/vercel"
  dependency-version: 9.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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Author: dependabot[bot]