chore: Format playground

Author: gonfunko

packages/blockly/tests/playgrounds/web_component.html

@@ -147,9 +147,7 @@ <h1>Blockly Web Component/Shadow DOM Playground</h1>
 
     <div id="workspaces">
       <div class="workspace-card">
-        <div class="workspace-card-header">
-          Light DOM
-        </div>
+        <div class="workspace-card-header">Light DOM</div>
         <div class="workspace-card-body">
           <div id="blocklyDiv-normal"></div>
         </div>