As of MySQL 8.0.17, the UNSIGNED attribute is deprecated for columns of type FLOAT, DOUBLE, and DECIMAL (and any synonyms) and you should expect support for it to be removed in a future version of MySQL.
Yeah, that's one of them. Looks like some others are deprecated that didn't show up for me when I did a manual backup earlier today. Probably safe to ignore for now though, just something that needs to be addressed by the time they actually remove that functionality