Remove days as allowed unit in Absolute.difference
Remove days as allowed unit in Absolute.difference

#859 forgot to update the TS type declarations to remove `days`
as a valid value for `largestUnit` in `Absolute.prototype.difference`.

https://github.com/tc39/proposal-temporal/pull/894
js-temporal/temporal-polyfill,js-temporal/temporal-polyfill,js-temporal/temporal-polyfill