Stack Dependencies Transitive Stack Dir Dependency

Resolve transitive autoinclude dependencies on a stack directory

run --all no longer fails with "does not contain a terragrunt.hcl file" when an autoinclude dependency points at a stack directory (one holding terragrunt.stack.hcl) and the unit is reached transitively through another unit. The dependency cycle check now skips a target with no unit config, matching the direct dependency case.