message: remove flag definition dupes
diff: -from absl import flags
  -
  -from xain.benchmark.net import model_fns
  -
  -flags.DEFINE_string("model", None, f"Model name, one of {[fn for fn in model_fns]}")
  -flags.DEFINE_string("dataset", None, "Dataset name")
  -flags.DEFINE_integer("B", None, "Batch size")
  -flags.DEFINE_integer("partition_id", None, "Partition ID for unitary training")
  