Gradle module output configuration for test dependencies only

I have a Gradle project containing the two modules app and test, where test contains utilities for testing only. Now I'd like to setup this module, so it doesn't include any outputs into the main configuration of app; even not accidentally.

implementation project(':test') # should fail or not contain any inputs

testImplementation project(':test') # should include all inputs
androidTestImplementation project(':test') # should include all inputs

How do I configure test to behave like this?

I'd assume it would be similarly to how the Android plugin handles configurations for build types and flavors, but I'm also not sure on how to figure this out.

from Gradle module output configuration for test dependencies only