The recently-vacated Shopko store in Quincy will soon be home to a Dollar Tree location. Muinicipal Services Director Carl Worley says the single-price retailer will take up half of the former Shopko’s 37,000 square feet. Negotiations are said to be under way to land a tenant for the other half of the building but it’s not been made public what business that tenant is in. The new Dollar Tree is to open by the end of the month.