BlockContentSelectionExtendsRector

Entity reference selection plugins for block_content that extend DefaultSelection must extend BlockContentSelection instead, to avoid the deprecated automatic reusable-block filtering hook.

 use Drupal\Core\Entity\Attribute\EntityReferenceSelection;
 use Drupal\Core\Entity\Plugin\EntityReferenceSelection\DefaultSelection;
 use Drupal\Core\StringTranslation\TranslatableMarkup;

 #[EntityReferenceSelection(
   id: "mymodule:block_content",
   label: new TranslatableMarkup("My block content selection"),
   group: "mymodule",
   entity_types: ["block_content"],
 )]
-class MyBlockContentSelection extends DefaultSelection {
+class MyBlockContentSelection extends \Drupal\block_content\Plugin\EntityReferenceSelection\BlockContentSelection {
 }

Configure your rector.php:

<?php

use DrupalRector\Drupal11\Rector\Deprecation\BlockContentSelectionExtendsRector;
use Rector\Config\RectorConfig;

return RectorConfig::configure()
    ->withRules([
        BlockContentSelectionExtendsRector::class,
    ]);

Other rules in the drupal/core 11.4 set