build(deps): bump the js-dependencies group across 1 directory with 4 updates

Bumps the js-dependencies group with 4 updates in the /docs-starlight directory: [@astrojs/starlight](https://github.com/withastro/starlight/tree/HEAD/packages/starlight), [@astrojs/vercel](https://github.com/withastro/astro/tree/HEAD/packages/integrations/vercel), [astro](https://github.com/withastro/astro/tree/HEAD/packages/astro) and [@types/bun](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/bun).


Updates `@astrojs/starlight` from 0.35.1 to 0.35.2
- [Release notes](https://github.com/withastro/starlight/releases)
- [Changelog](https://github.com/withastro/starlight/blob/main/packages/starlight/CHANGELOG.md)
- [Commits](https://github.com/withastro/starlight/commits/@astrojs/[email protected]/packages/starlight)

Updates `@astrojs/vercel` from 8.2.3 to 8.2.5
- [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/@astrojs/[email protected]/packages/integrations/vercel)

Updates `astro` from 5.12.3 to 5.12.9
- [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/[email protected]/packages/astro)

Updates `@types/bun` from 1.2.19 to 1.2.20
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/bun)

---
updated-dependencies:
- dependency-name: "@astrojs/starlight"
  dependency-version: 0.35.2
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: js-dependencies
- dependency-name: "@astrojs/vercel"
  dependency-version: 8.2.5
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: js-dependencies
- dependency-name: astro
  dependency-version: 5.12.9
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: js-dependencies
- dependency-name: "@types/bun"
  dependency-version: 1.2.20
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: js-dependencies
...

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

Author: dependabot[bot]