OTTAWA (Reuters) – Canada, Britain, Sweden and Ukraine on Monday formally complained to the U.N. aviation council in their bid to hold Iran accountable for the downing of a passenger airliner in January 2020 that killed 176 people, they said on Monday. Most of the dead were citizens from the four nations, which created a coordination group that seeks to hold Iran to account. “Today we have jointly initiated dispute-settlement proceedings before the International Civil Aviation Organization against the Islamic Republic of Iran for using weapons against a civil aircraft in flight,” they said in …