Enable Global Styles functionality in classic WordPress themes, allowing features like the Font Library to work without requiring a theme.json file. This change: - Removes restrictions that prevented classic themes from accessing Global Styles features. - Enables font functionality in classic themes through the Font Library. - Fixes Fonts menu not appearing in classic themes by changing its submenu index to avoid collision with Widgets. Props youknowriad, isabel_brison, ramonopoly. Fixes #64408. Built from https://develop.svn.wordpress.org/trunk@61473 git-svn-id: http://core.svn.wordpress.org/trunk@60785 1a063a9b-81f0-0310-95a4-ce76da25c4cd