Make Kafka integration tests more reliable

[markfarkas-camunda]

Is your feature request related to a problem? Please describe.

We cannot upgrade the testcontainers kafka docker image version for the integration tests, because it makes the test unreliable. Meaning: sometimes it fails, sometimes it passes.
I don't know whether the order of publishing or the order of consuming or the time of correlation changes but something does, and therefore the order of getting the correlated messages also changes, making the test unreliable, in their current state.

Describe the solution you'd like

Tests should be less order dependent.

Describe alternatives you've considered

Alternative would be to not update the docker image version, but we would like to be up-to-date.

Additional context

Issue was discovered as part of this PR: #926 when docker image was changed to confluentinc/cp-kafka:7.4.0