Issue #3488134: Add type="button" to action buttons

Closes #3488134

components/alert/alert.twig

@@ -12,6 +12,6 @@
     {{ message }}
   {% if dismissible %}
     {% set close_title = close_title|default('Close'|t) %}
-    <button{% if dismissible == 'core' %} onclick="const alert = this.parentNode; alert.parentNode.removeChild(alert);"{% endif %} class="fr-btn fr-btn--close" title="{{ close_title }}">{{ close_title }}</button>
+    <button{% if dismissible == 'core' %} onclick="const alert = this.parentNode; alert.parentNode.removeChild(alert);"{% endif %} class="fr-btn fr-btn--close" title="{{ close_title }}" type="button">{{ close_title }}</button>
   {% endif %}
 </div>