Follow-up from "Fix bulk_update_integration_service foreign_key"

The following discussion from !73456 (merged) should be addressed:

• @.luke started a discussion:

  Thought

  🤔 The specs in the file tend to create objects like this, rather than by using a factory. Given we don't have a :group trait for our integrations factories, I think it'll be fine to create this group integration as you are for now. I'll create a follow-up issue to make a :group trait and then to make use of factories for this spec.