deps: bump the dependency-updates group with 3 updates

Bumps the dependency-updates group with 3 updates: [eslint-mdx](https://github.com/mdx-js/eslint-mdx), [eslint-plugin-mdx](https://github.com/mdx-js/eslint-mdx) and [@prettier/sync](https://github.com/prettier/prettier-synchronized).


Updates `eslint-mdx` from 3.2.0 to 3.3.1
- [Release notes](https://github.com/mdx-js/eslint-mdx/releases)
- [Changelog](https://github.com/mdx-js/eslint-mdx/blob/master/CHANGELOG.md)
- [Commits](https://github.com/mdx-js/eslint-mdx/compare/[email protected]@3.3.1)

Updates `eslint-plugin-mdx` from 3.2.0 to 3.3.1
- [Release notes](https://github.com/mdx-js/eslint-mdx/releases)
- [Changelog](https://github.com/mdx-js/eslint-mdx/blob/master/CHANGELOG.md)
- [Commits](https://github.com/mdx-js/eslint-mdx/compare/[email protected]@3.3.1)

Updates `@prettier/sync` from 0.5.4 to 0.5.5
- [Release notes](https://github.com/prettier/prettier-synchronized/releases)
- [Commits](prettier/prettier-synchronized@v0.5.4...v0.5.5)

---
updated-dependencies:
- dependency-name: eslint-mdx
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: dependency-updates
- dependency-name: eslint-plugin-mdx
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: dependency-updates
- dependency-name: "@prettier/sync"
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: dependency-updates
...

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

Author: dependabot[bot]