Create variable collapseHeadingId to standardize the heading tag Id.

Closes #3477408

templates/ui-kit/accordions/accordions.macros.twig

@@ -3,8 +3,9 @@
   {% set id = random(0, 10000) %}
   <div class="accordion" id="{{ 'accordion-' ~ id }}">
     {% for i in 1..numItems %}
+      {% set collapseHeadingId = 'collapse__heading-' ~ id ~ '-' ~ loop.index %}
       <div class="accordion-item">
-        <{{ headerAs|default('h2') }} class="accordion-header" id="#{{ 'collapse__heading-' ~ id }}">
+        <{{ headerAs|default('h2') }} class="accordion-header" id="{{ collapseHeadingId }}">
           <button class="accordion-button {{ collapsed is not same as(true) and loop.index == 1 ? '' : 'collapsed'}}"
                   type="button"
                   data-bs-toggle="collapse"
@@ -17,7 +18,7 @@
 
         <div id="{{ 'collapse-' ~ id ~ loop.index }}"
              class="accordion-collapse collapse {{ collapsed is not same as(true) and loop.index == 1 ? 'show' : ''}}"
-             aria-labelledby="#{{ 'collapse__heading-' ~ id ~ loop.index }}"
+             aria-labelledby="#{{ collapseHeadingId }}"
           {% if alwaysOpen %} data-bs-parent="#accordion-{{ id }}" {% endif %}>
           <div class="accordion-body">
             {% trans %}