Use link elements

Problem/Motivation

Just a suggestion: while working on 🐛 [pp1] Improve cacheability metadata Postponed , particularly the link cacheability aspect, I found myself wondering why it doesn't use link elements (which handle the cacheability for you) in \Drupal\prevnext\PrevNextService::buildEntityLinks().

Proposed resolution

Use link elements.

Remaining tasks

API changes