The December Dew Tour stop is always a big one for the best snowboarders and freestyle skiers and for the fans who come to party and watch. In an Olympic season like this, it is even bigger — a key Olympic qualifying event for many athletes and a strong peek at what to expect come February. If this year’s event in Copper Mountain, Colo., was an indication, the competition in the halfpipe and the slopestyle course at the 2022 Beijing Winter Games is going to be tight, filled with bigger…