Bump phpunit/phpunit from 8.4.2 to 8.5.2 (#181)

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 8.4.2 to 8.5.2.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/master/ChangeLog-8.5.md)
- [Commits](sebastianbergmann/phpunit@8.4.2...8.5.2)

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

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