ISSUE-30286 - Change layout update removal button rendering from a block to directly in the template to prevent inaccurate js element selection in SecureHtmlRenderer event listener generation.

Author: Zach Nanninga

app/code/Magento/Widget/Block/Adminhtml/Widget/Instance/Edit/Tab/Main/Layout.php

@@ -315,25 +315,6 @@ public function getAddLayoutButtonHtml()
         return $button->toHtml();
     }
 
-    /**
-     * Retrieve remove layout button html
-     *
-     * @return string
-     */
-    public function getRemoveLayoutButtonHtml()
-    {
-        $button = $this->getLayout()->createBlock(
-            \Magento\Backend\Block\Widget\Button::class
-        )->setData(
-            [
-                'label' => $this->escapeHtmlAttr(__('Remove Layout Update')),
-                'onclick' => 'WidgetInstance.removePageGroup(this)',
-                'class' => 'action-delete',
-            ]
-        );
-        return $button->toHtml();
-    }
-
     /**
      * Prepare and retrieve page groups data of widget instance
      *

app/code/Magento/Widget/view/adminhtml/templates/instance/edit/layout.phtml

@@ -38,7 +38,8 @@ var pageGroupTemplate = '<div class="fieldset-wrapper page_group_container" id="
         '<label for="widget_instance[<%- data.id %>][page_group]">Display on <span class="required">*</span></label>'+
         '{$block->getDisplayOnSelectHtml()}'+
         '<div class="actions">'+
-        {$jsonHelper->jsonEncode($block->getRemoveLayoutButtonHtml())} +
+            '<button title="{$escaper->escapeHtmlAttr(__('Remove Layout Update'))}" type="button"'+
+            '    class="action-default scalable action-delete" onclick="WidgetInstance.removePageGroup(this)" />'+
         '</div>'+
     '</div>'+
     '<div class="fieldset-wrapper-content">'+