build(deps): bump @mdx-js/mdx from 1.6.5 to 1.6.16

Bumps [@mdx-js/mdx](https://github.com/mdx-js/mdx) from 1.6.5 to 1.6.16.
- [Release notes](https://github.com/mdx-js/mdx/releases)
- [Changelog](https://github.com/mdx-js/mdx/blob/master/changelog.md)
- [Commits](mdx-js/mdx@v1.6.5...v1.6.16)

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