Bump symfony/phpunit-bridge from 5.2.0 to 5.2.1

Bumps [symfony/phpunit-bridge](https://github.com/symfony/phpunit-bridge) from 5.2.0 to 5.2.1.
- [Release notes](https://github.com/symfony/phpunit-bridge/releases)
- [Changelog](https://github.com/symfony/phpunit-bridge/blob/5.x/CHANGELOG.md)
- [Commits](symfony/phpunit-bridge@v5.2.0...v5.2.1)

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