[ruby/reline] Remove an obsolete commented-out test

https://github.com/ruby/reline/commit/5354d02e03

test/reline/test_key_actor_emacs.rb

@@ -2287,29 +2287,4 @@ class Reline::KeyActor::Emacs::Test < Reline::TestCase
     assert_cursor(1)
     assert_cursor_max(1)
   end
-
-=begin # TODO: move KeyStroke instance from Reline to LineEditor
-  def test_key_delete
-    input_keys('ab')
-    assert_byte_pointer_size('ab')
-    assert_cursor(2)
-    assert_cursor_max(2)
-    assert_line('ab')
-    [27, 91, 51, 126].each do |key|
-      @line_editor.input_key(key)
-    end
-    assert_byte_pointer_size('ab')
-    assert_cursor(2)
-    assert_cursor_max(2)
-    assert_line('ab')
-    input_keys("\C-b")
-    [27, 91, 51, 126].each do |key|
-      @line_editor.input_key(key)
-    end
-    assert_byte_pointer_size('a')
-    assert_cursor(1)
-    assert_cursor_max(1)
-    assert_line('a')
-  end
-=end
 end