Bump astro from 4.16.3 to 5.0.3 in /website in the dependabot group

Bumps the dependabot group in /website with 1 update: [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro).


Updates `astro` from 4.16.3 to 5.0.3
- [Release notes](https://github.com/withastro/astro/releases)
- [Changelog](https://github.com/withastro/astro/blob/main/packages/astro/CHANGELOG.md)
- [Commits](https://github.com/withastro/astro/commits/astro@5.0.3/packages/astro)

---
updated-dependencies:
- dependency-name: astro
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: dependabot
...

Signed-off-by: dependabot[bot] <support@github.com>