Remove redundant begin block

We have `Style/RedundantBegin` cop (#34764) but it could not correct in
this case.

railties/test/generators/app_generator_test.rb

@@ -681,7 +681,7 @@ def test_inclusion_of_listen_related_configuration_by_default
   def test_inclusion_of_listen_related_configuration_on_other_rubies
     ruby_engine = Object.send(:remove_const, :RUBY_ENGINE)
     Object.const_set(:RUBY_ENGINE, "MyRuby")
-    begin
+
     run_generator
     if RbConfig::CONFIG["host_os"] =~ /darwin|linux/
       assert_listen_related_configuration
@@ -692,7 +692,6 @@ def test_inclusion_of_listen_related_configuration_on_other_rubies
     Object.send(:remove_const, :RUBY_ENGINE)
     Object.const_set(:RUBY_ENGINE, ruby_engine)
   end
-  end
 
   def test_non_inclusion_of_listen_related_configuration_if_skip_listen
     run_generator [destination_root, "--skip-listen"]