Bump objectbox-gradle-plugin from 2.8.1 to 2.9.0 in /project
Bump objectbox-gradle-plugin from 2.8.1 to 2.9.0 in /project

Bumps [objectbox-gradle-plugin](https://github.com/objectbox/objectbox-java) from 2.8.1 to 2.9.0.
- [Release notes](https://github.com/objectbox/objectbox-java/releases)
- [Commits](https://github.com/objectbox/objectbox-java/compare/V2.8.1...V2.9.0)

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