Allow primary key attributes

This improvement went out too quickly, so let's undo it.

Lots of the work around it was great and we want to keep that, so this
surgically snips out:

- The README describing the feature.
- The ActiveRecordValidator that implements the validation.
- The railtie code that loaded the validator.

It leaves the validation framework and the notification code.

README.md

@@ -152,22 +152,6 @@ rails generate factory_bot:model NAME [field:type field:type] [options]
 
 [default factory template]: https://github.com/thoughtbot/factory_bot_rails/tree/main/lib/generators/factory_bot/model/templates/factories.erb
 
-### Active Record Configuration
-
-By default, FactoryBot will refuse to generate Active Record primary key
-columns. Without additional configuration, an Active Record model treats a
-column named `id` as its primary key.
-
-For example, defining an `id` attribute with `add_attribute(:id)`, `id { ... }`,
-or `sequence(:id)` will raise a `FactoryBot::AttributeDefinitionError`.
-
-You can disable this behavior by adding the following to the appropriate environment configuration in `config/environments`
-e.g. `config/environments/test.rb`:
-
-```ruby
-config.factory_bot.reject_primary_key_attributes = false
-```
-
 ## Contributing
 
 Please see [CONTRIBUTING.md](CONTRIBUTING.md).

lib/factory_bot_rails/railtie.rb

@@ -10,7 +10,6 @@ module FactoryBotRails
   class Railtie < Rails::Railtie
     config.factory_bot = ActiveSupport::OrderedOptions.new
     config.factory_bot.definition_file_paths = FactoryBot.definition_file_paths
-    config.factory_bot.reject_primary_key_attributes = true
     config.factory_bot.validator = FactoryBotRails::FactoryValidator.new
 
     initializer "factory_bot.set_fixture_replacement" do
@@ -21,18 +20,6 @@ class Railtie < Rails::Railtie
       FactoryBot.definition_file_paths = definition_file_paths
     end
 
-    initializer "factory_bot.reject_primary_key_attributes" do
-      ActiveSupport.on_load :active_record do
-        config = Rails.configuration.factory_bot
-
-        if config.reject_primary_key_attributes
-          require "factory_bot_rails/factory_validator/active_record_validator"
-
-          config.validator.add_validator FactoryValidator::ActiveRecordValidator.new
-        end
-      end
-    end
-
     config.after_initialize do |app|
       FactoryBot.find_definitions
       Reloader.new(app).run