By Nandita Bose, Humeyra Pamuk and Matt Spetalnick WASHINGTON (Reuters) -After months of painstaking negotiations with Moscow, it became clear to President Joe Biden’s administration that it faced a grave choice – to exchange notorious Russian arms dealer Viktor Bout for U.S. basketball star Brittney Griner or else get no American to bring home. Thursday’s prisoner swap, approved personally by Biden, came together in the past 48 hours, U.S. officials said, sending Griner from a Russian penal colony to Moscow and then to an airport in the United Arab Emirates. Excluded from the deal was another…