[Docs Site] Bump @astrojs/react from 3.6.2 to 4.0.0

Bumps [@astrojs/react](https://github.com/withastro/astro/tree/HEAD/packages/integrations/react) from 3.6.2 to 4.0.0.
- [Release notes](https://github.com/withastro/astro/releases)
- [Changelog](https://github.com/withastro/astro/blob/main/packages/integrations/react/CHANGELOG.md)
- [Commits](https://github.com/withastro/astro/commits/@astrojs/[email protected]/packages/integrations/react)

---
updated-dependencies:
- dependency-name: "@astrojs/react"
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]