(PUP-11993) Style/VariableInterpolation

This commit enables the Style/VariableInterpolation cop and fixes
1 autocorrectable offense.

Author: AriaXLi

.rubocop_todo.yml

@@ -762,12 +762,6 @@ Style/TrailingUnderscoreVariable:
 Style/TrivialAccessors:
   Enabled: false
 
-# This cop supports safe auto-correction (--auto-correct).
-Style/VariableInterpolation:
-  Exclude:
-    - 'lib/puppet/util/command_line/trollop.rb'
-    - 'lib/puppet/util/rdoc/generators/puppet_generator.rb'
-
 # This cop supports safe auto-correction (--auto-correct).
 Style/WhenThen:
   Enabled: false

lib/puppet/util/command_line/trollop.rb

@@ -491,7 +491,7 @@ def educate stream = $stdout
       rightcol_start = leftcol_width + 6 # spaces
 
       unless @order.size > 0 && @order.first.first == :text
-        stream.puts "#@version\n" if @version
+        stream.puts "#{@version}\n" if @version
         stream.puts _("Options:")
       end