Bump symfony/security-core from 4.2.8 to 4.2.9
Bump symfony/security-core from 4.2.8 to 4.2.9

Bumps [symfony/security-core](https://github.com/symfony/security-core) from 4.2.8 to 4.2.9.
- [Release notes](https://github.com/symfony/security-core/releases)
- [Commits](https://github.com/symfony/security-core/compare/v4.2.8...v4.2.9)
alcohol/paste.robbast.nl,alcohol/sf-minimal-demo,alcohol/paste.robbast.nl,alcohol/paste.robbast.nl