[Dependency] bump symfony/routing from 4.3.3 to 4.3.4 in /site (#4401)
[Dependency] bump symfony/routing from 4.3.3 to 4.3.4 in /site (#4401)

Bumps [symfony/routing](https://github.com/symfony/routing) from 4.3.3 to 4.3.4.
- [Release notes](https://github.com/symfony/routing/releases)
- [Changelog](https://github.com/symfony/routing/blob/master/CHANGELOG.md)
- [Commits](https://github.com/symfony/routing/compare/v4.3.3...v4.3.4)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
RCOS-Grading-Server/HWserver,RCOS-Grading-Server/HWserver,RCOS-Grading-Server/HWserver,Submitty/Submitty,RCOS-Grading-Server/HWserver,Submitty/Submitty,Submitty/Submitty,Submitty/Submitty,RCOS-Grading-Server/HWserver,Submitty/Submitty,Submitty/Submitty,Submitty/Submitty,RCOS-Grading-Server/HWserver,RCOS-Grading-Server/HWserver,RCOS-Grading-Server/HWserver,RCOS-Grading-Server/HWserver,Submitty/Submitty,Submitty/Submitty