Issue #3185419: Code style updates

src/Form/WorkflowTypeConfigureForm.php

 <?php
 
+declare(strict_types = 1);
+
 namespace Drupal\workflows_field\Form;
 
 use Drupal\Core\Form\FormStateInterface;
@@ -7,14 +9,14 @@ use Drupal\workflows\Plugin\WorkflowTypeConfigureFormBase;
 use Drupal\workflows\State;
 
 /**
- * Plugin form for the workflows field.
+ * Plugin configuration form for the "Workflows Field" workflow type.
  */
 class WorkflowTypeConfigureForm extends WorkflowTypeConfigureFormBase {
 
   /**
    * {@inheritdoc}
    */
-  public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
+  public function buildConfigurationForm(array $form, FormStateInterface $form_state): array {
     $configuration = $this->workflowType->getConfiguration();
     $form['settings'] = [
       '#title' => $this->t('Workflow Settings'),
@@ -24,7 +26,7 @@ class WorkflowTypeConfigureForm extends WorkflowTypeConfigureFormBase {
     $form['settings']['initial_state'] = [
       '#title' => $this->t('Initial State'),
       '#type' => 'select',
-      '#default_value' => isset($configuration['initial_state']) ? $configuration['initial_state'] : NULL,
+      '#default_value' => $configuration['initial_state'] ?? NULL,
       '#options' => $labels,
     ];
     return $form;
@@ -33,7 +35,7 @@ class WorkflowTypeConfigureForm extends WorkflowTypeConfigureFormBase {
   /**
    * {@inheritdoc}
    */
-  public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
+  public function submitConfigurationForm(array &$form, FormStateInterface $form_state): void {
     $configuration = $this->workflowType->getConfiguration();
     $configuration['initial_state'] = $form_state->getValue(['settings', 'initial_state']);
     $this->workflowType->setConfiguration($configuration);