Bundled Themes: Update Twenty Twenty.

This brings trunk’s version of Twenty Twenty in-sync with GitHub.

For a complete list of changes since [46571], see https://github.com/WordPress/twentytwenty/compare/4549fd9...dea9290.

Props anlino, ianbelanger, poena, williampatton, collet, erikkroes, torres126, intimez, byalextran, mehidi258, swapnild, nielslange.
Fixes #48450.
Built from https://develop.svn.wordpress.org/trunk@46613


git-svn-id: https://core.svn.wordpress.org/trunk@46410 1a063a9b-81f0-0310-95a4-ce76da25c4cd