Suppress InternalAffairs/RedundantContextConfigParameter offenses

Follow up of rubocop/rubocop#10412.

This commit suppresses the following offenses.

```console
% bundle exec rubocop -a
(snip)

Offenses:

spec/rubocop/cop/rails/application_job_spec.rb:4:34: C: [Corrected]
InternalAffairs/RedundantContextConfigParameter: Remove the redundant
:config parameter.
context 'Rails 4.2', :rails42, :config do
^^^^^^^
spec/rubocop/cop/rails/application_mailer_spec.rb:4:34: C: [Corrected]
InternalAffairs/RedundantContextConfigParameter: Remove the redundant
:config parameter.
context 'Rails 4.2', :rails42, :config do
^^^^^^^
spec/rubocop/cop/rails/application_record_spec.rb:4:34: C: [Corrected]
InternalAffairs/RedundantContextConfigParameter: Remove the redundant
:config parameter.
context 'Rails 4.2', :rails42, :config do
^^^^^^^
spec/rubocop/cop/rails/http_positional_arguments_spec.rb:4:34: C:
[Corrected] InternalAffairs/RedundantContextConfigParameter: Remove the
redundant :config parameter.
context 'Rails 4.2', :rails42, :config do
^^^^^^^

236 files inspected, 4 offenses detected, 4 offenses corrected
```

Author: koic

spec/rubocop/cop/rails/application_job_spec.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 RSpec.describe RuboCop::Cop::Rails::ApplicationJob, :config, :config do
-  context 'Rails 4.2', :rails42, :config do
+  context 'Rails 4.2', :rails42 do
     it 'allows ApplicationJob to be defined' do
       expect_no_offenses(<<~RUBY)
         class ApplicationJob < ActiveJob::Base

spec/rubocop/cop/rails/application_mailer_spec.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 RSpec.describe RuboCop::Cop::Rails::ApplicationMailer, :config, :config do
-  context 'Rails 4.2', :rails42, :config do
+  context 'Rails 4.2', :rails42 do
     it 'allows `ApplicationMailer` to be defined' do
       expect_no_offenses(<<~RUBY)
         class ApplicationMailer < ActionMailer::Base; end

spec/rubocop/cop/rails/application_record_spec.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 RSpec.describe RuboCop::Cop::Rails::ApplicationRecord, :config, :config do
-  context 'Rails 4.2', :rails42, :config do
+  context 'Rails 4.2', :rails42 do
     it 'allows ApplicationRecord to be defined' do
       expect_no_offenses(<<~RUBY)
         class ApplicationRecord < ActiveRecord::Base; end

spec/rubocop/cop/rails/http_positional_arguments_spec.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 RSpec.describe RuboCop::Cop::Rails::HttpPositionalArguments, :config, :config do
-  context 'Rails 4.2', :rails42, :config do
+  context 'Rails 4.2', :rails42 do
     it 'does not register an offense for get method' do
       expect_no_offenses('get :create, user_id: @user.id')
     end