Bump FluentValidation from 8.3.0 to 8.4.0
Bump FluentValidation from 8.3.0 to 8.4.0

Bumps [FluentValidation](https://github.com/JeremySkinner/fluentvalidation) from 8.3.0 to 8.4.0.
- [Release notes](https://github.com/JeremySkinner/fluentvalidation/releases)
- [Changelog](https://github.com/JeremySkinner/FluentValidation/blob/master/Changelog.txt)
- [Commits](https://github.com/JeremySkinner/fluentvalidation/compare/8.3.0...8.4.0)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
Fody/FodyAddinSamples,Fody/FodyAddinSamples