[CodingStyle] Remove next node attribute on NewlineAfterStatementRector

[samsonasik]

This remove AttributeKey::NEXT_NODE usage on NewlineAfterStatementRector,

Benefit

• It works on continuation index on docblock updated by other rules, see https://github.com/rectorphp/rector-src/pull/3525/files#diff-aa536cd048c4df5690eafdcaf0e4d065c11a262fb23ebce04dafc0f527e72238

Limitation

• this no longer work on spacing new line for multiple namespaces,eg:

namespace A{}
namespace B{}

as there is no parent of namespace to loop, see https://github.com/rectorphp/rector-src/pull/3525/files#diff-6169f918307ebebbb7127ccd6c653513c3269acb124e30add820d370fe3a0eac

Ref rectorphp/rector#7849

[samsonasik]

All checks have passed 🎉 @TomasVotruba it is ready for review.

[TomasVotruba]

Thank you 👏 👏 👏