Adopt `DefaultReactiveEntityCallbacksUnitTests` to Java 18's `IllegalArgumentException` as marker for incompatible lambda payload

[michael-simons]

The DefaultReactiveEntityCallbacksUnitTests has not been enhanced In #2583 to capture IllegalArgumentException that are the result when a lambda-defined listener for which the generic event type for could not be resolved gets called.

This is the case of the issues in this ticket at SDN spring-projects/spring-data-neo4j#2701

[odrotbohm]

This is fixed by merging your PR. Note that we further improve the handling of Lambda-based EntityCallback declarations in #2812.