Fix Google Tag Manager URL in Third Party Libraries documentation (#57731)
## Description
Updating the URL for the Google Tag Manager in the Next.js documentation for [Third Party Libraries](https://nextjs.org/docs/pages/building-your-application/optimizing/third-party-libraries).
We were using https://developers.google.com/maps/documentation/embed/embedding-map, which redirected to the documentation for embedding Google Maps.
## Implementation
- Replacing https://developers.google.com/maps/documentation/embed/embedding-map by https://developers.google.com/tag-platform/tag-manager