Bump symfony/event-dispatcher from 4.2.8 to 4.2.9
Bump symfony/event-dispatcher from 4.2.8 to 4.2.9

Bumps [symfony/event-dispatcher](https://github.com/symfony/event-dispatcher) from 4.2.8 to 4.2.9.
- [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/v4.2.8...v4.2.9)
thecoolestguy/ilios,Trott/ilios,Trott/ilios,ilios/ilios,dartajax/ilios,thecoolestguy/ilios,stopfstedt/ilios,stopfstedt/ilios,dartajax/ilios,ilios/ilios