Add compiler error for integer_primary_key with Ets

[brianhv]

Following up on this message in discord.

When using the ETS data layer and an integer_primary_key, rows get inserted with id: nil, and rows after the first will clobber the previous rows. In Discord it was suggested that this situation ought to be a compile time error.

Example of code with which I observed the issue:

defmodule Campdbash.Camper do
  use Ash.Resource,
    domain: Campdbash,
    data_layer: Ash.DataLayer.Ets

  actions do
    defaults [:read]

    create :register do
      accept [:first_name, :last_name]
    end
  end

  attributes do
    uuid_primary_key :id

    attribute :first_name, :string do
      allow_nil? false
    end

    attribute :last_name, :string do
      allow_nil? false
    end

  end
end

Inserted with

Campdbash.Camper |> Ash.Changeset.for_create(:register, %{first_name: "fname", last_name: "lname"}) |> Ash.create!()

Result

#Campdbash.Camper<
  __meta__: #Ecto.Schema.Metadata<:loaded>,
  id: nil,
  first_name: "fname",
  last_name: "lname",
  aggregates: %{},
  calculations: %{},
  ...
>