Bump symfony/event-dispatcher from 4.2.7 to 4.2.8
Bump symfony/event-dispatcher from 4.2.7 to 4.2.8

Bumps [symfony/event-dispatcher](https://github.com/symfony/event-dispatcher) from 4.2.7 to 4.2.8.
- [Release notes](https://github.com/symfony/event-dispatcher/releases)
- [Changelog](https://github.com/symfony/event-dispatcher/blob/master/CHANGELOG.md)
- [Commits](https://github.com/symfony/event-dispatcher/compare/v4.2.7...v4.2.8)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
alcohol/paste.robbast.nl,alcohol/paste.robbast.nl,alcohol/paste.robbast.nl,alcohol/sf-minimal-demo