Fix RSpec/VariableDefinition rubocop offense

.rubocop_todo.yml

@@ -213,13 +213,6 @@ RSpec/ReturnFromStub:
 RSpec/ScatteredLet:
   Enabled: false
 
-# Offense count: 10
-# Configuration parameters: EnforcedStyle.
-# SupportedStyles: symbols, strings
-RSpec/VariableDefinition:
-  Exclude:
-    - 'spec/initializers/mail_encoding_patch_spec.rb'
-
 # Offense count: 24
 # Configuration parameters: EnforcedStyle, IgnoredPatterns.
 # SupportedStyles: snake_case, camelCase

spec/initializers/mail_encoding_patch_spec.rb

 # frozen_string_literal: true
+# rubocop:disable RSpec/VariableDefinition
 
 require 'fast_spec_helper'
 
@@ -205,3 +206,4 @@ RSpec.describe 'Mail quoted-printable transfer encoding patch and Unicode charac
     end
   end
 end
+# rubocop:enable RSpec/VariableDefinition