Fix M2M100 with batched input

Author: jonatanklosko

lib/bumblebee/text/m2m100.ex

@@ -437,14 +437,18 @@ defmodule Bumblebee.Text.M2m100 do
   end
 
   defnp sinusoidal_position_embedding_impl(position_ids, opts \\ []) do
+    position_ids = Nx.vectorize(position_ids, :batch)
+
     size = opts[:size]
 
     half_size = div(size, 2)
     base = 10_000
     range = Nx.iota({half_size}) / (half_size - 1)
     inv_frequency = 1 / Nx.pow(base, range)
     angle = Nx.outer(position_ids, inv_frequency)
-    Nx.concatenate([Nx.sin(angle), Nx.cos(angle)], axis: -1)
+    sin_cos = Nx.concatenate([Nx.sin(angle), Nx.cos(angle)], axis: -1)
+
+    Nx.devectorize(sin_cos)
   end
 
   defp decoder(