chore(deps-dev): Bump php-coveralls/php-coveralls

Bumps [php-coveralls/php-coveralls](https://github.com/php-coveralls/php-coveralls) from 2.9.0 to 2.9.1.
- [Release notes](https://github.com/php-coveralls/php-coveralls/releases)
- [Changelog](https://github.com/php-coveralls/php-coveralls/blob/master/CHANGELOG.md)
- [Commits](php-coveralls/php-coveralls@v2.9.0...v2.9.1)

---
updated-dependencies:
- dependency-name: php-coveralls/php-coveralls
  dependency-version: 2.9.1
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]