Build/Test Tools: Replace the banner text from `wp-emoji-loader.min.js` in...

Build/Test Tools: Replace the banner text from `wp-emoji-loader.min.js` in `formatting.php` during build process.

This ensures that `/*! This file is auto-generated */` comment is not included on front end as part of the inline Emoji detection script.

Follow-up to [41271], [46589].

Props superpoincare, SergeyBiryukov.
Fixes #49861.
Built from https://develop.svn.wordpress.org/trunk@48096


git-svn-id: https://core.svn.wordpress.org/trunk@47865 1a063a9b-81f0-0310-95a4-ce76da25c4cd