Can I avoid a dependency cycle with one edge being a test dependency?

You can't resolve this conflict with Maven or with any other build tool. It's not a build tool issue, it is an architectural flaw and can only be addressed through refactoring.

Two options come immediately to mind:

1) Create a new module called "test_common" that contains the stuff that both TestFramework need and DummyCore need. The make test_common a dependency of both of those modules.

2) Move the stuff that TestFramework needs from DummyCore into TestFramework. Then TestFramework depends on nothing and DummyCore depends on TestFramework.

There are many ways to solve this, but circular inter-module dependencies are a big time NO-NO regardless of language or build tool.