Base field purging is not handling translatable fields correctly

Problem/Motivation

When uninstalling a module that adds a custom base field definition to a entity that has been translated into more than one language, the process crashes and the module is unable to be uninstalled:

Drupal\Core\Database\IntegrityConstraintViolationException: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '3-21-1-0-es'; for key 'PRIMARY': INSERT INTO {field_deleted_revision_fd812c0eda} (bundle, entity_id, revision_id, langcode, my_field_value, deleted, delta) SELECT base_table.type AS bundle, entity_table.nid AS entity_id, entity_table.vid AS revision_id, entity_table.langcode AS langcode, entity_table.my_field AS my_field_value, :deleted AS deleted, :delta AS delta
FROM
{node_field_data} entity_table
INNER JOIN {node_field_data} base_table ON entity_table.nid = base_table.nid
WHERE entity_table.my_field IS NOT NULL FOR UPDATE;

Steps to reproduce

1. Add a second language to the site.
2. Install the Content Translation module.
3. Enable content translation for Basic Page.
4. Install a module that adds a base field to the node entity type. (Sample hook below, full sample module attached.)
5. Create a basic page.
6. Add a translation of the page in the second language.
7. Edit the page, check the "My field" checkbox, and save the page.
8. Uninstall the module that added the base field definition.

Expected result: Module is uninstalled, and the my_field column is dropped from the node_field_data table.
Actual result: Error message above.

Sample module:

use Drupal\Core\Entity\EntityTypeInterface;
use Drupal\Core\Field\BaseFieldDefinition;

/**
 * Implements hook_entity_base_field_info().
 */
function mymodule_entity_base_field_info(EntityTypeInterface $entity_type) {
  if ($entity_type->id() == 'node') {
    $fields['my_field'] = BaseFieldDefinition::create('boolean')
      ->setLabel(t('My field'))
      ->setDisplayConfigurable('form', TRUE)
      ->setDisplayOptions('form', [
        'type' => 'boolean_checkbox',
        'weight' => 100,
      ]);
    return $fields;
  }
}

Proposed resolution

The error appears to be caused by a query in which the node_field_data is JOINed on itself by id, but not langcode, causing duplicate rows. I don't fully understand the purpose of the JOIN, but my workaround is to add the langcode as a JOIN condition. (Patch attached.)