don't render the shortTitle inside Page.render (#33922)

lib/page.js

@@ -179,9 +179,6 @@ class Page {
     this.title = await renderContentWithFallback(this, 'rawTitle', context, {
       textOnly: true,
     })
-    this.shortTitle = await renderContentWithFallback(this, 'shortTitle', context, {
-      textOnly: true,
-    })
 
     const html = await renderContentWithFallback(this, 'markdown', context)