ST. PAUL, Minn. — The Minnesota Supreme Court has declined to take up challenges by tribal and conservation groups to the environmental review of Enbridge Energy’s proposal for replacing its aging Line 3 crude oil pipeline across northern Minnesota. The court rejected the requests in a one-page order Tuesday. The project could have faced a long delay if the high court had agreed to hear the appeals. Calgary, Alberta-based Enbridge says the decision means that the Public Utilities Commission can now move forward with addressing one deficiency in the environmental impact statement identified by the Minnesota Court of Appeals. That court upheld most of the environmental review in June, but sent the case back to the PUC for further work because the review did not address a possible spill in the Lake Superior watershed.