js: Prevent that collapsible buttons submit forms

application/layouts/scripts/layout.phtml

@@ -69,7 +69,7 @@ $innerLayoutScript = $this->layout()->innerLayout . '.phtml';
   }());
 </script>
 <div id="collapsible-control-ghost" class="collapsible-control">
-    <button>
+    <button type="button">
         <?= $this->icon('angle-double-down', $this->translate('Expand'), ['class' => 'expand-icon']) ?>
         <?= $this->icon('angle-double-up', $this->translate('Collapse'), ['class' => 'collapse-icon']) ?>
     </button>