MADISON, Wis. — Conservatives on the Wisconsin Supreme Court ruled Thursday that a conservation group couldn’t challenge an agency’s decision to sell state park land for the construction of a high-end golf course along the shores of Lake Michigan.Opponents said the ruling will make it much harder for the public to challenge decisions of state agencies.The court’s 4-3 ruling said that the Friends of the Black River Forest can’t challenge the Department of Natural Resources policy board’s …