Bump unified from 10.1.2 to 11.0.3 in /test/util

Bumps [unified](https://github.com/unifiedjs/unified) from 10.1.2 to 11.0.3.
- [Release notes](https://github.com/unifiedjs/unified/releases)
- [Changelog](https://github.com/unifiedjs/unified/blob/main/changelog.md)
- [Commits](unifiedjs/unified@10.1.2...11.0.3)

---
updated-dependencies:
- dependency-name: unified
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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