Replace rails_helper.rb with spec_helper.rb

rails_helper.rb's only logic was to require
spec_helper.rb.

.rubocop.yml

@@ -264,8 +264,6 @@ RSpec/EnvAssignment:
   Exclude:
     - 'spec/**/fast_spec_helper.rb'
     - 'ee/spec/**/fast_spec_helper.rb'
-    - 'spec/**/rails_helper.rb'
-    - 'ee/spec/**/rails_helper.rb'
     - 'spec/**/spec_helper.rb'
     - 'ee/spec/**/spec_helper.rb'
 RSpec/BeSuccessMatcher:

bin/rspec-stackprof

@@ -3,7 +3,7 @@
 require 'bundler/setup'
 require 'stackprof'
 $:.unshift 'spec'
-require 'rails_helper'
+require 'spec_helper'
 filename = ARGV[0].split('/').last
 interval = ENV.fetch('INTERVAL', 1000).to_i

doc/development/gotchas.md

@@ -18,7 +18,7 @@ end
 Consider the following API spec:
 ```ruby
-require 'rails_helper'
+require 'spec_helper'
 describe API::Labels do
   it 'creates a first label' do
@@ -69,7 +69,7 @@ is ok, but `create(:label, title: 'label1')` is not.
 Following is the fixed API spec:
 ```ruby
-require 'rails_helper'
+require 'spec_helper'
 describe API::Labels do
   it 'creates a first label' do

spec/controllers/projects/blob_controller_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe Projects::BlobController do
   include ProjectForksHelper

spec/controllers/sent_notifications_controller_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe SentNotificationsController do
   let(:user) { create(:user) }

spec/features/admin/admin_disables_git_access_protocol_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe 'Admin disables Git access protocol', :js do
   include StubENV

spec/features/admin/admin_disables_two_factor_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe 'Admin disables 2FA for a user' do
   it 'successfully', :js do

spec/features/admin/admin_uses_repository_checks_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe 'Admin uses repository checks' do
   include StubENV

spec/features/boards/add_issues_modal_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe 'Issue Boards add issue modal', :js do
   let(:project) { create(:project, :public) }

spec/features/boards/boards_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe 'Issue Boards', :js do
   include DragTo

spec/features/boards/issue_ordering_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe 'Issue Boards', :js do
   include DragTo

spec/features/boards/keyboard_shortcut_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe 'Issue Boards shortcut', :js do
   context 'issues are enabled' do

spec/features/boards/modal_filter_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe 'Issue Boards add issue modal filtering', :js do
   let(:project) { create(:project, :public) }

spec/features/boards/multiple_boards_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe 'Multiple Issue Boards', :js do
   set(:user) { create(:user) }

spec/features/boards/new_issue_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe 'Issue Boards new issue', :js do
   let(:project) { create(:project, :public) }

spec/features/boards/reload_boards_on_browser_back_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe 'Ensure Boards do not show stale data on browser back', :js do
   let(:project) {create(:project, :public)}

spec/features/boards/sidebar_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe 'Issue Boards', :js do
   include BoardHelpers

spec/features/boards/sub_group_project_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe 'Sub-group project issue boards', :js do
   let(:group) { create(:group) }

spec/features/commits/user_uses_quick_actions_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe 'Commit > User uses quick actions', :js do
   include Spec::Support::Helpers::Features::NotesHelpers

spec/features/dashboard/todos/target_state_spec.rb

 # frozen_string_literal: true
-require 'rails_helper'
+require 'spec_helper'
 describe 'Dashboard > Todo target states' do
   let(:user)    { create(:user) }