build(deps-dev): bump symfony/phpunit-bridge from 6.3.6 to 6.3.8

Bumps [symfony/phpunit-bridge](https://github.com/symfony/phpunit-bridge) from 6.3.6 to 6.3.8.
- [Release notes](https://github.com/symfony/phpunit-bridge/releases)
- [Changelog](https://github.com/symfony/phpunit-bridge/blob/6.3/CHANGELOG.md)
- [Commits](symfony/phpunit-bridge@v6.3.6...v6.3.8)

---
updated-dependencies:
- dependency-name: symfony/phpunit-bridge
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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