Add todo on form table header code block in theme file

From #3111409: Add new Olivero frontend theme to Drupal 9.1 core as beta

 +++ b/core/themes/olivero/olivero.theme
@@ -0,0 +1,576 @@
+    $variables['table']['#header'][0]['data'] = [
+      '#type' => 'html_tag',
+      '#tag' => 'h4',
+      '#value' => $variables['element']['#title'],
+      '#attributes' => $header_attributes,
+    ];

Let's add a todo to change this after #3099026: Claro's preprocessing of field multiple value form's table header cell removes potential changes by others has landed