[Fix #6566] Fix a false positive for Layout/EmptyLinesAroundAccessModifier

[koic]

Fixes #6566.

This PR fixes a false positive for Layout/EmptyLinesAroundAccessModifier when at the end of specifying a superclass is missing blank line.

The following is originally no offense code.
(It is probably a regression by #6307 💦)

% cat example.rb
class SomeController < SomeOtherController
  def index; end

  private
end

% rubocop example.rb --only Layout/EmptyLinesAroundAccessModifier -a
Inspecting 1 file
C

Offenses:

example.rb:4:3: C: [Corrected] Layout/EmptyLinesAroundAccessModifier:
Keep a blank line before and after private.
  private
  ^^^^^^^

1 file inspected, 1 offense detected, 1 offense corrected

Auto-correct adds a blank line after private. This is due to false positives.

 % cat example.rb
 class SomeController < SomeOtherController
   def index; end

   private
+
 end

This caused the infinite loop in Layout/EmptyLinesAroundAccessModifier and Layout/EmptyLinesAroundClassBody.

% rubocop example.rb --only Layout/EmptyLinesAroundClassBody -a
Inspecting 1 file
C

Offenses:

example.rb:5:1: C: [Corrected] Layout/EmptyLinesAroundClassBody: Extra
empty line detected at class body end.

1 file inspected, 1 offense detected, 1 offense corrected

Auto-correct removes the blank line from after of private.

 % cat example.rb
 class SomeController < SomeOtherController
   def index; end

   private
-
 end

It loops to the first code. This PR fixes the infinite loop.

---

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• Squashed related commits together.
• Added tests.
• Added an entry to the Changelog if the new code introduces user-observable changes. See changelog entry format.
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[Drenmi]

🚀

[bbatsov]

Thanks!