I just created a uBlock origin rule. It seems the extension gets the same job done by removing all HTML elements with the class "xA33Gc" or "K7JcSb" (source: https://github.com/Jtfinlay/gsearch-hidefavicon/blob/master/...).

In uBlock Origin one could add the rules:

www.google.com##.TbwUpd > .xA33Gc www.google.com##.TbwUpd > .K7JcSb

Or more generally: www.google.com##.TbwUpd > img

to hide the icons...