Make io.helidon.microprofile.tests:helidon-microprofile-tests-junit5 inherit from io.helidon.microprofile:helidon-microprofile-project instead of io.helidon.microprofile.tests:tests-project.
io.helidon.microprofile.tests:tests-project is not deployed to Maven and thus cannot be in the parent pom chain of any pom that needs to be deployed (otherwise effective pom resolution fails).