CONAKRY (Reuters) -Guinea is set to vote on Sunday in a referendum on a new constitution that would permit junta leader Mamady Doumbouya to run for president, something he vowed not to do when he seized power four years ago. Wednesday is the final day of campaigning for the referendum, the latest attempt at a political transition in West and Central Africa, where eight coups between 2020 and 2023 reshaped the regional political landscape. A transition charter adopted after the September 2021 coup said junta members would be barred from standing in the next national and local elections, but the new constitution does not include that language.