Dear Winter, we’re through. So say Bostonians after a season that’s already one for the record books. The numbers tell the story: 69 inches of snow in 30 days, with 37 inches on the ground now. Already 2015 will go down as one of the top 10 snowiest winters in city history, with six weeks left. It’s not just the annoyance factor, but classes and work canceled and buildings buckling — at least one sheet metal shop collapsed. One day they’ll see the ground again.