japiCmp Gradle task does not have a relocatable build cache

[jprinet]

If you run the JapiCmp task from 2 different folders with the same inputs, you can't benefit from Gradle build cache as one of the input (richReport.rules's Map) is using an absolute path as value.

In my cache relocation experience, the cost was 33 tasks executed in 33 projects totaling 39.212s building micronaut-core: ./gradlew clean check -x :http-server-netty:test