Dataform unset policy tags

[dali-rmw]

We manage policy tags using a tool other than Dataform. The issue is that when we run our pipeline, Dataform removes the policy tags already attached. I believe it would be better if Dataform didn't update the policy tags unless they are explicitly set in the column attributes.

[Ekrekr]

That sounds very reasonable!

This would probably be best as a workflow settings option, so that users can choose