Bump vaadin.version in /mhu-lib-examples/vaadin/FormsTest03
Bump vaadin.version in /mhu-lib-examples/vaadin/FormsTest03

Bumps `vaadin.version` from 8.6.1 to 8.12.4.

Updates `vaadin-server` from 8.6.1 to 8.12.4
- [Release notes](https://github.com/vaadin/framework/releases)
- [Commits](https://github.com/vaadin/framework/compare/8.6.1...8.12.4)

Updates `vaadin-compatibility-server` from 8.6.1 to 8.12.4
- [Release notes](https://github.com/vaadin/framework/releases)
- [Commits](https://github.com/vaadin/framework/compare/8.6.1...8.12.4)

Updates `vaadin-client-compiled` from 8.6.1 to 8.12.4
- [Release notes](https://github.com/vaadin/framework/releases)
- [Commits](https://github.com/vaadin/framework/compare/8.6.1...8.12.4)

Updates `vaadin-compatibility-client-compiled` from 8.6.1 to 8.12.4
- [Release notes](https://github.com/vaadin/framework/releases)
- [Commits](https://github.com/vaadin/framework/compare/8.6.1...8.12.4)

Updates `vaadin-themes` from 8.6.1 to 8.12.4
- [Release notes](https://github.com/vaadin/framework/releases)
- [Commits](https://github.com/vaadin/framework/compare/8.6.1...8.12.4)

Updates `vaadin-compatibility-themes` from 8.6.1 to 8.12.4
- [Release notes](https://github.com/vaadin/framework/releases)
- [Commits](https://github.com/vaadin/framework/compare/8.6.1...8.12.4)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
mhus/mhus-examples,mhus/mhus-examples,mhus/mhus-examples,mhus/mhus-examples