https://www.drupal.org/node/3419963

Introduced in branch/version: 10.3.x / 10.3.0

Symfony\Component\DependencyInjection\ContainerAwareTrait And Symfony\Component\DependencyInjection\ContainerAwareInterface are being deprecated in Symfony 6.4 and removed in 7.0.

Both Drupal\Core\DependencyInjection\ClassResolver and Drupal\Core\Entity\EntityTypeManager depend on retrieving any arbitrary service from the container, so they still need full access to the container.

We now inject the service_container as an argument in their constructor, instead of making them ContainerAware.

Drupal\Core\DependencyInjection\ClassResolver before:

$class_resolver = new ClassResolver();
$class_resolver->setContainer($container);

Drupal\Core\DependencyInjection\ClassResolver after:

$class_resolver = new ClassResolver($container);

Drupal\Core\Entity\EntityTypeManager before:

$entity_type_manager = new EntityTypeManager($namespaces,  $module_handler, $cache, $string_translation, $class_resolver, $entity_last_installed_schema_repository);

Drupal\Core\Entity\EntityTypeManager after:

$entity_type_manager = new EntityTypeManager($namespaces, $module_handler, $cache, $string_translation, $class_resolver, $entity_last_installed_schema_repository, $container);

The setContainer methods in both classes are now deprecated and will be removed from Drupal 11.0.0.