WASHINGTON — The Biden administration will take a historic step toward easing federal restrictions on cannabis, with plans to announce an interim rule soon reclassifying the drug for the first time since the Controlled Substances Act was enacted more than 50 years ago, four sources with knowledge of the decision said. The Drug Enforcement Administration is expected to approve an opinion by the Department of Health and Human Services that marijuana should be reclassified from the strictest Schedule I to the less stringent Schedule III. It would be the first time that the U.S. government has acknowledged its potential medical...