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

spec/spec_helper.rb

@@ -6,6 +6,8 @@ RSpec.configure do |config|
     expectations.include_chain_clauses_in_custom_matcher_descriptions = true
   end
 
+  config.disable_monkey_patching!
+
   config.mock_with :rspec do |mocks|
     mocks.verify_partial_doubles = true
   end