Use include_tasks rather than import_tasks

[alanbchristie]

Evaluation of include_tasks occurs when the tasks are encountered whereas import_tasks is evaluated statically, and prior to evaluating any variables. Consequently, if you're dependent of variables during the import then it may fail, i.e. doing something like this will fail: -

- import_tasks: finalise-{{ data_source_out }}.yaml

As a general policy ... use include_tasks unless there's an important reason why import_tasks is being used. And, if using import_tasks add a comment as to why include_tasks is not being used.