Enable Layout/EmptyLinesAroundAccessModifier cop

We sometimes say "✂️ newline after `private`" in a code review (e.g.
rails#18546 (comment),
rails#34832 (comment)).

Now `Layout/EmptyLinesAroundAccessModifier` cop have new enforced style
`EnforcedStyle: only_before` (rubocop/rubocop#7059).

That cop and enforced style will reduce the our code review cost.

Author: kamipo

.rubocop.yml

@@ -61,6 +61,10 @@ Layout/EndAlignment:
 Layout/EmptyLineAfterMagicComment:
   Enabled: true
 
+Layout/EmptyLinesAroundAccessModifier:
+  Enabled: true
+  EnforcedStyle: only_before
+
 Layout/EmptyLinesAroundBlockBody:
   Enabled: true
 

actioncable/lib/action_cable/server/worker.rb

@@ -66,7 +66,6 @@ def invoke(receiver, method, *args, connection:, &block)
       end
 
       private
-
         def logger
           ActionCable.server.logger
         end