Fix Drupal.Commenting.FunctionComment.MissingReturnComment in core/lib/Drupal/Core/A-E

Problem/Motivation

Fix the sniff for some file paths in core/lib

Steps to reproduce

Proposed resolution

This adds a comment in most cases. There are a few like the following that use an ignore line instead. This retains the more specific return type which mstrlen states assists with static analysis.

  /**
   * {@inheritdoc}
   *
   * @return \Drupal\Core\Entity\EntityTypeInterface[]
   */
  // phpcs:ignore Drupal.Commenting.FunctionComment.MissingReturnComment
  public function getDefinitions();

Remaining tasks

Perhaps add a followup for the ignore lines or rely on existing work to add return type hints.

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet