Replace references to deprecated device_buffer attributes

`jax.Array.device_buffer` and `jax.Array.device_buffers` will be deprecated as of jax version 0.4.22; see jax-ml/jax#18844.

PiperOrigin-RevId: 588553845

trax/optimizers/trainer.py

@@ -445,9 +445,11 @@ def _free_accelerators(self, exceptions=(), keep_constants=True):
     logging.info('Deleting %d live buffers.', len(live_buffers))
     exceptions_buffers = []
     for x in fastmath.tree_flatten(exceptions):
-      if hasattr(x, 'device_buffer'):  # DeviceArray
+      if hasattr(x, 'addressable_shards'):  # Array
+        exceptions_buffers.extend(shard.data for shard in x.addressable_shards)
+      elif hasattr(x, 'device_buffer'):  # DeviceArray
         exceptions_buffers.append(x.device_buffer)
-      if hasattr(x, 'device_buffers'):  # ShardedDeviceArray
+      elif hasattr(x, 'device_buffers'):  # ShardedDeviceArray
         exceptions_buffers.extend(x.device_buffers)
     for b in live_buffers:
       should_delete = True