Bump nuxt and @nuxt/content

Bumps [nuxt](https://github.com/nuxt/nuxt/tree/HEAD/packages/nuxt) and [@nuxt/content](https://github.com/nuxt/content). These dependencies needed to be updated together.

Updates `nuxt` from 3.21.6 to 4.5.0
- [Commits](https://github.com/nuxt/nuxt/commits/v4.5.0/packages/nuxt)

Updates `@nuxt/content` from 2.13.4 to 3.15.2
- [Release notes](https://github.com/nuxt/content/releases)
- [Changelog](https://github.com/nuxt/content/blob/main/CHANGELOG.md)
- [Commits](nuxt/content@v2.13.4...v3.15.2)

---
updated-dependencies:
- dependency-name: nuxt
  dependency-version: 4.5.0
  dependency-type: direct:production
- dependency-name: "@nuxt/content"
  dependency-version: 3.15.2
  dependency-type: direct:production
...

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Author: dependabot[bot]