Bump MahApps.Metro from 2.4.0 to 2.4.3
Bump MahApps.Metro from 2.4.0 to 2.4.3

Bumps [MahApps.Metro](https://github.com/MahApps/MahApps.Metro) from 2.4.0 to 2.4.3.
- [Release notes](https://github.com/MahApps/MahApps.Metro/releases)
- [Changelog](https://github.com/MahApps/MahApps.Metro/blob/develop/GitReleaseManager.yaml)
- [Commits](https://github.com/MahApps/MahApps.Metro/compare/2.4.0...2.4.3)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
fluentribbon/Fluent.Ribbon,fluentribbon/Fluent.Ribbon