Fix isRequired error in GoToCodeButton.propTypes (#6646)

Skip `PdfSynctexControls` rendering until `position` is set

GitOrigin-RevId: ea40c7f98ea3bbdf3d8689175658d2c014b68436

services/web/frontend/js/features/pdf-preview/components/pdf-synctex-controls.js

@@ -312,6 +312,10 @@ function PdfSynctexControls() {
     }
   }, [syncToCode])
 
+  if (!position) {
+    return null
+  }
+
   if (!pdfExists || pdfViewer === 'native') {
     return null
   }