Remove HasIntegrations module

This module should need to be namespaced into concerns/integrations,
however, it is a module that can only be applied to projects, and the
single class method mirrors Group.without_integrations which is written
in-class.

https://gitlab.com/gitlab-org/gitlab/-/issues/330670

app/models/concerns/has_integrations.rb

-# frozen_string_literal: true
-
-module HasIntegrations
-  extend ActiveSupport::Concern
-
-  class_methods do
-    def without_integration(integration)
-      integrations = Integration
-        .select('1')
-        .where("#{Integration.table_name}.project_id = projects.id")
-        .where(type: integration.type)
-
-      Project
-        .where('NOT EXISTS (?)', integrations)
-        .where(pending_delete: false)
-        .where(archived: false)
-    end
-  end
-end

app/models/project.rb

@@ -19,7 +19,6 @@ class Project < ApplicationRecord
   include Presentable
   include HasRepository
   include HasWiki
-  include HasIntegrations
   include CanMoveRepositoryStorage
   include Routable
   include GroupDescendant
@@ -860,6 +859,18 @@ class Project < ApplicationRecord
     rescue ActionController::RoutingError, URI::InvalidURIError
       nil
     end
+
+    def without_integration(integration)
+      integrations = Integration
+        .select('1')
+        .where("#{Integration.table_name}.project_id = projects.id")
+        .where(type: integration.type)
+
+      Project
+        .where('NOT EXISTS (?)', integrations)
+        .where(pending_delete: false)
+        .where(archived: false)
+    end
   end
 
   def initialize(attributes = nil)

spec/models/concerns/has_integrations_spec.rb

-# frozen_string_literal: true
-
-require 'spec_helper'
-
-RSpec.describe HasIntegrations do
-  let_it_be(:project_1) { create(:project) }
-  let_it_be(:project_2) { create(:project) }
-  let_it_be(:project_3) { create(:project) }
-  let_it_be(:project_4) { create(:project) }
-  let_it_be(:instance_integration) { create(:jira_integration, :instance) }
-
-  before do
-    create(:jira_integration, project: project_1, inherit_from_id: instance_integration.id)
-    create(:jira_integration, project: project_2, inherit_from_id: nil)
-    create(:jira_integration, :group, group: create(:group), inherit_from_id: nil)
-    create(:jira_integration, project: project_3, inherit_from_id: nil)
-    create(:integrations_slack, project: project_4, inherit_from_id: nil)
-  end
-
-  describe '.without_integration' do
-    it 'returns projects without integration' do
-      expect(Project.without_integration(instance_integration)).to contain_exactly(project_4)
-    end
-  end
-end

spec/models/project_spec.rb

@@ -1864,6 +1864,20 @@ RSpec.describe Project, factory_default: :keep do
     end
   end
 
+  describe '.without_integration' do
+    it 'returns projects without the integration' do
+      project_1, project_2, project_3, project_4 = create_list(:project, 4)
+      instance_integration = create(:jira_integration, :instance)
+      create(:jira_integration, project: project_1, inherit_from_id: instance_integration.id)
+      create(:jira_integration, project: project_2, inherit_from_id: nil)
+      create(:jira_integration, group: create(:group), project: nil, inherit_from_id: nil)
+      create(:jira_integration, project: project_3, inherit_from_id: nil)
+      create(:integrations_slack, project: project_4, inherit_from_id: nil)
+
+      expect(Project.without_integration(instance_integration)).to contain_exactly(project_4)
+    end
+  end
+
   context 'repository storage by default' do
     let(:project) { build(:project) }