Block attribute class expecting wrong ContextDefinition

Problem/Motivation

The $context_definitions param for the Block attribute is expecting \Drupal\Core\Annotation\ContextDefinition[]. This was added in #3252386: Use PHP attributes instead of doctrine annotations, yet in #3421019: Convert SectionStorage plugin discovery to attributes we're expecting \Drupal\Component\Plugin\Context\ContextDefinitionInterface[], which the previously mentioned class does not inherit from. It's possibly been mixed up with \Drupal\Core\Plugin\Context\ContextDefinition. Note the similar name but different namespace.

Steps to reproduce

The following attribute causes phpstan grief:

#[Block(
  id: "my_block",
  admin_label: new TranslatableMarkup("My block."),
  context_definitions: [
    'node' => new EntityContextDefinition(
      data_type: 'entity:node',
      label: 'Node Context',
      required: FALSE,
    ),
  ],
)]

Proposed resolution

• Confirm which class/interface we're meant to use
• Fix it

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet