Enable "zero monkey patching" mode in RSpec (#31614)

spec/serializers/rest/account_serializer_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe REST::AccountSerializer do
+RSpec.describe REST::AccountSerializer do
   subject { serialized_record_json(account, described_class) }
 
   let(:role)    { Fabricate(:user_role, name: 'Role', highlighted: true) }

spec/serializers/rest/encrypted_message_serializer_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe REST::EncryptedMessageSerializer do
+RSpec.describe REST::EncryptedMessageSerializer do
   let(:serialization) { serialized_record_json(record, described_class) }
   let(:record) { Fabricate(:encrypted_message) }
 

spec/serializers/rest/instance_serializer_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe REST::InstanceSerializer do
+RSpec.describe REST::InstanceSerializer do
   let(:serialization) { serialized_record_json(record, described_class) }
   let(:record) { InstancePresenter.new }
 

spec/serializers/rest/keys/claim_result_serializer_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe REST::Keys::ClaimResultSerializer do
+RSpec.describe REST::Keys::ClaimResultSerializer do
   let(:serialization) { serialized_record_json(record, described_class) }
   let(:record) { Keys::ClaimService::Result.new(Account.new(id: 123), 456) }
 

spec/serializers/rest/keys/device_serializer_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe REST::Keys::DeviceSerializer do
+RSpec.describe REST::Keys::DeviceSerializer do
   let(:serialization) { serialized_record_json(record, described_class) }
   let(:record) { Device.new(name: 'Device name') }
 

spec/serializers/rest/keys/query_result_serializer_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe REST::Keys::QueryResultSerializer do
+RSpec.describe REST::Keys::QueryResultSerializer do
   let(:serialization) { serialized_record_json(record, described_class) }
   let(:record) { Keys::QueryService::Result.new(Account.new(id: 123), []) }
 

spec/serializers/rest/suggestion_serializer_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe REST::SuggestionSerializer do
+RSpec.describe REST::SuggestionSerializer do
   let(:serialization) { serialized_record_json(record, described_class) }
   let(:record) do
     AccountSuggestions::Suggestion.new(