Bump xtend.version from 2.14.0 to 2.15.0 in /ch.vorburger.xtendbeans
Bump xtend.version from 2.14.0 to 2.15.0 in /ch.vorburger.xtendbeans

Bumps `xtend.version` from 2.14.0 to 2.15.0.

Updates `org.eclipse.xtend.lib` from 2.14.0 to 2.15.0
- [Release notes](https://github.com/eclipse/xtext-lib/releases)
- [Commits](https://github.com/eclipse/xtext-lib/compare/v2.14.0...v2.15.0)

Updates `xtend-maven-plugin` from 2.14.0 to 2.15.0

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
vorburger/xtendbeans