By Parisa Hafezi VIENNA (Reuters) -Efforts to revive Iran’s 2015 nuclear deal cannot succeed unless Washington lifts “major” sanctions, Iranian President Ebrahim Raisi said on Monday, as sources said indirect talks between Iran and the United States were reaching a final stage. Reuters reported last week that a U.S.-Iranian deal is taking shape in Vienna after months of indirect talks to revive the nuclear pact abandoned in 2018 by then-U.S. President Donald Trump, who also reimposed extensive sanctions on Iran. “The United States must prove its will to lift major sanctions,” Raisi said at a j…