Updates the requirements on [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) to permit the latest version.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/master/ChangeLog-9.4.md)
- [Commits](https://github.com/sebastianbergmann/phpunit/compare/9.0.0...9.4.0)

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

• Commit 02fcbc1
• #25: Update phpunit/phpunit requirement from ^9.0 to ^9.4
• Branch 1.2.x

dependabot[bot]