Migrate to JUnit5

[atai]

What feature do you want to see added?

Now I see the warnings when testing:

(1) [INFO] The JUnit Vintage engine is deprecated and should only be used temporarily while migrating tests to JUnit Jupiter or another testing framework with native JUnit Platform support.
Dec 30, 2025 11:33:33 AM org.junit.platform.launcher.core.DiscoveryIssueNotifier logIssues
INFO: TestEngine with ID 'junit-vintage' encountered a non-critical issue during test discovery:

need to be migrated to JUnit5

Upstream changes

No response

Are you interested in contributing this feature?

No response