Change record status: 
Description: 

Entity view builder plugins can now be defined using PHP 8.1+ attributes as an alternative to annotations. The existing annotation-based discovery continues to work.

What changed:

A new Drupal\pluggable_entity_view_builder\Attribute\EntityViewBuilder attribute class has been added, and EntityViewBuilderPluginManager has been updated to support attribute-based plugin discovery alongside the existing annotation-based discovery.

Plugins can now be defined with an attribute instead of an annotation:

  #[EntityViewBuilder(
    id: "node.article",
    label: new TranslatableMarkup("Node Article"),
    description: new TranslatableMarkup("Entity view builder for Article nodes."),
  )]
  class NodeArticle extends EntityViewBuilderPluginAbstract {

How to update your code:

No changes are required. Existing annotation-based plugins continue to work. You may optionally migrate your plugin definitions to use the new attribute syntax.