composer(deps): bump symfony/var-dumper from 7.1.6 to 7.1.8

Bumps [symfony/var-dumper](https://github.com/symfony/var-dumper) from 7.1.6 to 7.1.8.
- [Release notes](https://github.com/symfony/var-dumper/releases)
- [Changelog](https://github.com/symfony/var-dumper/blob/7.1/CHANGELOG.md)
- [Commits](symfony/var-dumper@v7.1.6...v7.1.8)

---
updated-dependencies:
- dependency-name: symfony/var-dumper
  dependency-type: indirect
  update-type: version-update:semver-patch
...

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