[Script] Updates stale no-script-in-document-page error doc (#37568)

[Recent changes](#31936) to `next/script` introduced the capability to use `beforeInteractive` scripts in the custom document. This old error message is incorrect.

errors/no-script-in-document-page.md

@@ -1,8 +1,10 @@
 # Script component inside \_document.js
 
+> ⚠️ This error is not relevant in versions 12.1.6 or later. Please refer to the updated [error message](https://nextjs.org/docs/messages/no-before-interactive-script-outside-document).
+
 #### Why This Error Occurred
 
-You can't use the `next/script` component inside the `_document.js` page. That's because the `_document.js` page only runs on the server and `next/script` has client-side functionality to ensure loading order.
+You can't use the `next/script` component inside the `_document.js` page in versions prior to v12.1.6. That's because the `_document.js` page only runs on the server and `next/script` has client-side functionality to ensure loading order.
 
 #### Possible Ways to Fix It