Ad hoc sequences in create_list

This comes up all the time. Here's an example from a real test:

prompts = [
  create(:prompt, name: "Prompt 1"),
  create(:prompt, name: "Prompt 2"),
  create(:prompt, name: "Prompt 3"),
]

I'd love to be able to write something else. Here's an example, maybe:

prompts = FactoryBot.create_list(
            :prompt,
            3,
            name: FactoryBot.build_sequence { |n| "Prompt #{n}" },
          )

Note that create_list already takes a block:

This block takes the produced object and the zero-based index as arguments, and returns an updated object.

But we want to get in there before it produces the object.

Start at create_list and trace how attributes are evaluated before the object is produced; compare the proposed build_sequence usage with the existing create_list block behavior. Done means create_list supports an ad hoc sequence for attributes while preserving its current block semantics, including the example shown.