Bump knplabs/github-api from 3.8.0 to 3.9.0

Bumps [knplabs/github-api](https://github.com/KnpLabs/php-github-api) from 3.8.0 to 3.9.0.
- [Release notes](https://github.com/KnpLabs/php-github-api/releases)
- [Changelog](https://github.com/KnpLabs/php-github-api/blob/master/CHANGELOG-3.X.md)
- [Commits](KnpLabs/php-github-api@v3.8.0...v3.9.0)

---
updated-dependencies:
- dependency-name: knplabs/github-api
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]