Bump symfony/var-dumper from 4.4.20 to 4.4.21 in /player
Bump symfony/var-dumper from 4.4.20 to 4.4.21 in /player

Bumps [symfony/var-dumper](https://github.com/symfony/var-dumper) from 4.4.20 to 4.4.21.
- [Release notes](https://github.com/symfony/var-dumper/releases)
- [Changelog](https://github.com/symfony/var-dumper/blob/5.x/CHANGELOG.md)
- [Commits](https://github.com/symfony/var-dumper/compare/v4.4.20...v4.4.21)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
blackfireio/player