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

spec/validators/email_mx_validator_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe EmailMxValidator do
+RSpec.describe EmailMxValidator do
   describe '#validate' do
     let(:user) { instance_double(User, email: 'foo@example.com', sign_up_ip: '1.2.3.4', errors: instance_double(ActiveModel::Errors, add: nil)) }
     let(:resolv_dns_double) { instance_double(Resolv::DNS) }

spec/validators/existing_username_validator_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe ExistingUsernameValidator do
+RSpec.describe ExistingUsernameValidator do
   let(:record_class) do
     Class.new do
       include ActiveModel::Validations

spec/validators/language_validator_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe LanguageValidator do
+RSpec.describe LanguageValidator do
   let(:record_class) do
     Class.new do
       include ActiveModel::Validations

spec/validators/note_length_validator_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe NoteLengthValidator do
+RSpec.describe NoteLengthValidator do
   subject { described_class.new(attributes: { note: true }, maximum: 500) }
 
   describe '#validate' do

spec/validators/reaction_validator_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe ReactionValidator do
+RSpec.describe ReactionValidator do
   let(:announcement) { Fabricate(:announcement) }
 
   describe '#validate' do

spec/validators/status_length_validator_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe StatusLengthValidator do
+RSpec.describe StatusLengthValidator do
   describe '#validate' do
     before { stub_const("#{described_class}::MAX_CHARS", 500) } # Example values below are relative to this baseline
 

spec/validators/unique_username_validator_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe UniqueUsernameValidator do
+RSpec.describe UniqueUsernameValidator do
   describe '#validate' do
     context 'when local account' do
       it 'does not add errors if username is nil' do

spec/validators/unreserved_username_validator_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe UnreservedUsernameValidator do
+RSpec.describe UnreservedUsernameValidator do
   let(:record_class) do
     Class.new do
       include ActiveModel::Validations

spec/validators/url_validator_spec.rb

@@ -2,7 +2,7 @@
 
 require 'rails_helper'
 
-describe URLValidator do
+RSpec.describe URLValidator do
   let(:record_class) do
     Class.new do
       include ActiveModel::Validations