Patches occasionally come in on generated files. We should be kind to new contributors and give them a hint that these files are auto-generated.
This is a follow-up to [41271], which added the banner to minified CSS files.
Fixes#48424. See #30666.
Built from https://develop.svn.wordpress.org/trunk@46589
git-svn-id: http://core.svn.wordpress.org/trunk@46386 1a063a9b-81f0-0310-95a4-ce76da25c4cd