Allbirds and Reformation, two of sustainable fashion’s buzziest brands, are making it part of their mission to eliminate endangered and old-growth forests from their clothing. On Tuesday, the labels joined 170 businesses—Abercrombie & Fitch, H&M, Patagonia, Stella McCartney and VF Corp. among them—in throwing their support behind CanopyStyle, an initiative by Canadian forestry not-for-profit Canopy…