build(deps-dev): bump phpunit/phpunit from 9.2.5 to 9.2.6 (#272)

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 9.2.5 to 9.2.6.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/master/ChangeLog-9.2.md)
- [Commits](sebastianbergmann/phpunit@9.2.5...9.2.6)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>