`javadoc:aggregate` fails with compile errors when multi-module project uses different version of the same dependency

[JackPGreen]

Affected version

3.12.0

Bug description

Imagine a multi-module project where different modules use different versions of the same dependency - e.g. connectors to version 1 and 2 of some service.

The javadoc:aggregate prunes the classpath supplied to the javadoc tool to include only the latest version of a dependency - which can lead to compile errors when referencing something exclusively in the older version.