Bump phpunit/phpunit from 7.5.10 to 7.5.11

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 7.5.10 to 7.5.11.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/master/ChangeLog-7.5.md)
- [Commits](https://github.com/sebastianbergmann/phpunit/compare/7.5.10...7.5.11

)

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