LibJS: Remove TODO() from implemented code path

Well, that's embarassing. TODO()'d it, implemented it, forgot to remove
the TODO().

Userland/Libraries/LibJS/Runtime/Temporal/TimeZone.cpp

@@ -557,7 +557,6 @@ ThrowCompletionOr<Instant*> disambiguate_possible_instants(GlobalObject& global_
 
     // 13. If disambiguation is "earlier", then
     if (disambiguation == "earlier"sv) {
-        TODO();
         // a. Let earlier be ? AddDateTime(dateTime.[[ISOYear]], dateTime.[[ISOMonth]], dateTime.[[ISODay]], dateTime.[[ISOHour]], dateTime.[[ISOMinute]], dateTime.[[ISOSecond]], dateTime.[[ISOMillisecond]], dateTime.[[ISOMicrosecond]], dateTime.[[ISONanosecond]], dateTime.[[Calendar]], 0, 0, 0, 0, 0, 0, 0, 0, 0, −nanoseconds, undefined).
         auto earlier = TRY(add_date_time(global_object, date_time.iso_year(), date_time.iso_month(), date_time.iso_day(), date_time.iso_hour(), date_time.iso_minute(), date_time.iso_second(), date_time.iso_millisecond(), date_time.iso_microsecond(), date_time.iso_nanosecond(), date_time.calendar(), 0, 0, 0, 0, 0, 0, 0, 0, 0, -nanoseconds, nullptr));