Autocomplete for EntityReference

Problem/Motivation

If an entity reference field is managed by a view and configured in autocomplete mode, an incomplete sentence is displayed.

File: web/core/modules/media/src/Hook/MediaHooks.php L208-216.
if ($is_autocomplete) {
$elements['#media_help']['#media_list_help'] = $this->t('Type part of the media name.');
$overview_url = Url::fromRoute('entity.media.collection');
if ($overview_url->access()) {
$elements['#media_help']['#media_list_link'] = $this->t('See the <a href=":list_url" target="_blank">media list</a> (opens a new window) to help locate media.', [':list_url' => $overview_url->toString()]);
}
$bundle_labels = array_intersect_key(\Drupal::service('entity_type.bundle.info')->getBundleLabels('media'), $allowed_bundles);
$elements['#media_help']['#allowed_types_help'] = $this->t('Allowed media types: %types', ['%types' => implode(", ", $bundle_labels)]);
}

The $bundle_labels variable is empty because a view is used. You can see the following sentence:
"Enter part of the media name. Consult the list of media (opens a new window) to help locate the media. Allowed media types: "

Steps to reproduce the issue

1. Install Drupal 11.4.1
2. Create content type A
3. Create content type B
4. Create an "entity reference" view based on content type B
5. Add an entity reference field to content type A
6. Configure the field's handler to use a view and select the view in question
7. In the form display section, configure this field to use autocomplete mode

Proposed resolution

Add a check for the handler method, or verify that $bundle_labels is not empty.

Remaining tasks

User interface changes

Introduced terminology

API changes

Data model changes

Release notes snippet