Bump axios and @tryghost/content-api in /nuxt-ghost

Bumps [axios](https://github.com/axios/axios) to 1.13.6 and updates ancestor dependency [@tryghost/content-api](https://github.com/TryGhost/SDK/tree/HEAD/packages/content-api). These dependencies need to be updated together.


Updates `axios` from 0.19.0 to 1.13.6
- [Release notes](https://github.com/axios/axios/releases)
- [Changelog](https://github.com/axios/axios/blob/v1.x/CHANGELOG.md)
- [Commits](axios/axios@v0.19.0...v1.13.6)

Updates `@tryghost/content-api` from 1.5.4 to 1.12.6
- [Commits](https://github.com/TryGhost/SDK/commits/@tryghost/content-api@1.12.6/packages/content-api)

---
updated-dependencies:
- dependency-name: axios
  dependency-version: 1.13.6
  dependency-type: indirect
- dependency-name: "@tryghost/content-api"
  dependency-version: 1.12.6
  dependency-type: direct:production
...

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Author: dependabot[bot]