add missing useJUnitPlatform() to make Gradle run JUnit 5 [FINERACT-1021]

[vorburger]

see #1020 and FINERACT-1021 ...

[vorburger]

This will fail with 14 integration test failures... 😢 @xurror I doubt you actually ran all tests in #1020.

The failures seems to be due to some parameter order mix up - I'm checking if I can easily fix them myself quickly. If not, I'll (have to..) sink more team into figuring out how to fully revert #1020 cleanly instead (PITA, just fixing is likely faster).

[xurror]

This will fail with 14 integration test failures... @xurror I doubt you actually ran all tests in #1020.

The failures seems to be due to some parameter order mix up - I'm checking if I can easily fix them myself quickly. If not, I'll (have to..) sink more team into figuring out how to fully revert #1020 cleanly instead (PITA, just fixing is likely faster).

I ran the tests, some must have excaped my vigilence. Thanks for your followup.