Bump github-username from 7.0.0 to 8.0.0

Bumps [github-username](https://github.com/sindresorhus/github-username) from 7.0.0 to 8.0.0.
- [Release notes](https://github.com/sindresorhus/github-username/releases)
- [Commits](sindresorhus/github-username@v7.0.0...v8.0.0)

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

Signed-off-by: dependabot[bot] <support@github.com>