build(deps): bump @nuxt/vite-builder and nuxt in /site (#244)

Bumps [@nuxt/vite-builder](https://github.com/nuxt/nuxt/tree/HEAD/packages/vite) to 3.15.3 and updates ancestor dependency [nuxt](https://github.com/nuxt/nuxt/tree/HEAD/packages/nuxt). These dependencies need to be updated together.


Updates `@nuxt/vite-builder` from 3.13.2 to 3.15.3
- [Release notes](https://github.com/nuxt/nuxt/releases)
- [Commits](https://github.com/nuxt/nuxt/commits/v3.15.3/packages/vite)

Updates `nuxt` from 3.13.2 to 3.15.3
- [Release notes](https://github.com/nuxt/nuxt/releases)
- [Commits](https://github.com/nuxt/nuxt/commits/v3.15.3/packages/nuxt)

---
updated-dependencies:
- dependency-name: "@nuxt/vite-builder"
  dependency-type: indirect
- dependency-name: nuxt
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>