CSS classes added to date input are also added to parent elements

Problem/Motivation

Using a form alter hook I have added a custom CSS class to a node form date input:

function test_module_form_node_form_alter(array &$form, FormStateInterface $form_state, string $form_id): void {
      $form['field_test_upload_date']['widget'][0]['value']['#attributes']['class'][] = 'TEST-CSS-CLASS';
}

The CSS class is added correctly to the form date input, but is also added to 2 parent div, .form-datetime-wrapper and .form-items-inline.

<div class="field--type-datetime field--name-field-test-upload-date field--widget-datetime-default js-form-wrapper form-wrapper" data-drupal-selector="edit-field-test-upload-date-wrapper" id="edit-field-test-upload-date-wrapper">
   <div class="TEST-CSS-CLASS form-item form-datetime-wrapper" data-drupal-selector="edit-field-test-upload-date-0-value">
      <h4 class="form-item__label">Test Upload Date</h4>
      <div id="edit-field-test-upload-date-0-value" class="TEST-CSS-CLASS form-items-inline" data-drupal-field-elements="date">
         <div class="js-form-item form-item js-form-type-date form-type--date js-form-item-field-test-upload-date-0-value-date form-item--field-test-upload-date-0-value-date form-item--no-label">
            <label for="edit-field-test-upload-date-0-value-date" class="form-item__label visually-hidden">Date</label>
            <input class="TEST-CSS-CLASS form-date form-element form-element--type-date form-element--api-date" data-drupal-selector="edit-field-test-upload-date-0-value-date" type="date" placeholder="YYYY-MM-DD" data-help="Enter the date using the format YYYY-MM-DD (e.g., 2024-06-10)." id="edit-field-test-upload-date-0-value-date" name="field_test_upload_date[0][value][date]" value="" size="12">
            </div>
         </div>
      </div>
   </div>

Steps to reproduce

1. Add a date field (not timestamp) to a content type
2. Use a form alter to add a custom CSS class to the form data input
3. Create a new node of the content type to view the edit form
4. The CSS class added should be on the element and 2 parent divs

Proposed resolution

Prevent CSS classes add to date inputs being added to related parent elements.

Remaining tasks

1. Confirm bug
2. Identify cause
3. Create MR with fix

User interface changes

None

API changes

None

Data model changes

None