In version 2.24.1 of tdewolff/minify, the KeepCSS2 option was deprecated in favor of Version, an integer where 0 represents the latest CSS version.

This change is simple to implement but raises a key question: Why was our KeepCSS2 default set to true? To accommodate this update, should we set the default Version to 2 to maintain the old default behavior, or should we switch to 0 to use the latest CSS standard? In either case, if the KeepCSS2 value is true, we need to set Version to 2.