Bump @mdx-js/loader from 2.1.3 to 3.0.0

Bumps [@mdx-js/loader](https://github.com/mdx-js/mdx/tree/HEAD/packages/loader) from 2.1.3 to 3.0.0.
- [Release notes](https://github.com/mdx-js/mdx/releases)
- [Changelog](https://github.com/mdx-js/mdx/blob/main/changelog.md)
- [Commits](https://github.com/mdx-js/mdx/commits/3.0.0/packages/loader)

---
updated-dependencies:
- dependency-name: "@mdx-js/loader"
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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