Fix includeDeLombokSources path

This should point to the project.build.directory and should not contain the target folder.
Property should also be used for getting the correct sources.

Locate the implementation of includeDeLombokSources and inspect how its source path is assembled and how project.build.directory is accessed. Confirm that the path uses the project build directory without an extra target segment and that the property supplies the source location. Done means the generated path is correct and the relevant build or plugin checks pass.

Written by the indexing model from the issue text.