Do not show header in playground

Author: ajhai

llmstack/client/src/pages/playground.jsx

@@ -19,7 +19,7 @@ const defaultPlaygroundLayout = `<pa-layout sx='{"width": "100%", "margin": "10p
   <pa-paper style="padding: 10px;">
     <pa-grid container="true" spacing="2" style="width: 100%">
       <pa-grid item="true" xs="2">
-        <pa-workflow-output showHeader="true"></pa-workflow-output>
+        <pa-workflow-output></pa-workflow-output>
       </pa-grid>
     </pa-grid>
   </pa-paper>