Revert to using FormElement instead of FormElementBase

src/Element/CheckboxTree.php

@@ -4,14 +4,14 @@ namespace Drupal\term_reference_tree\Element;
 
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Render\Element\CompositeFormElementTrait;
-use Drupal\Core\Render\Element\FormElementBase;
+use Drupal\Core\Render\Element\FormElement;
 
 /**
  * Provides a form element for term reference tree.
  *
  * @FormElement("checkbox_tree")
  */
-class CheckboxTree extends FormElementBase {
+class CheckboxTree extends FormElement {
 
   use CompositeFormElementTrait;
 

src/Element/CheckboxTreeItem.php

@@ -2,14 +2,14 @@
 
 namespace Drupal\term_reference_tree\Element;
 
-use Drupal\Core\Render\Element\FormElementBase;
+use Drupal\Core\Render\Element\FormElement;
 
 /**
  * Provides a form element for term reference tree.
  *
  * @FormElement("checkbox_tree_item")
  */
-class CheckboxTreeItem extends FormElementBase {
+class CheckboxTreeItem extends FormElement {
 
   /**
    * {@inheritdoc}

src/Element/CheckboxTreeLabel.php

@@ -2,14 +2,14 @@
 
 namespace Drupal\term_reference_tree\Element;
 
-use Drupal\Core\Render\Element\FormElementBase;
+use Drupal\Core\Render\Element\FormElement;
 
 /**
  * Provides a form element for term reference tree.
  *
  * @FormElement("checkbox_tree_label")
  */
-class CheckboxTreeLabel extends FormElementBase {
+class CheckboxTreeLabel extends FormElement {
 
   /**
    * {@inheritdoc}

src/Element/CheckboxTreeLevel.php

@@ -2,14 +2,14 @@
 
 namespace Drupal\term_reference_tree\Element;
 
-use Drupal\Core\Render\Element\FormElementBase;
+use Drupal\Core\Render\Element\FormElement;
 
 /**
  * Provides a form element for term reference tree.
  *
  * @FormElement("checkbox_tree_level")
  */
-class CheckboxTreeLevel extends FormElementBase {
+class CheckboxTreeLevel extends FormElement {
 
   /**
    * {@inheritdoc}

term_reference_tree.info.yml

 name: 'Term Reference Tree'
 description: 'An expanding/collapsing tree widget for selecting terms in a taxonomy term reference field.'
 package: Fields
-core_version_requirement: ^9.4 || ^10 || ^11 || ^12
+core_version_requirement: ^9.4 || ^10 || ^11
 dependencies:
   - drupal:taxonomy
 type: module