fix(utils): Convert observation values in predict_action to torch.Tensor (#1157)

Co-authored-by: Simon Alibert <75076266+aliberts@users.noreply.github.com>

lerobot/common/utils/control_utils.py

@@ -112,6 +112,7 @@ def predict_action(
     ):
         # Convert to pytorch format: channel first and float32 in [0,1] with batch dimension
         for name in observation:
+            observation[name] = torch.from_numpy(observation[name])
             if "image" in name:
                 observation[name] = observation[name].type(torch.float32) / 255
                 observation[name] = observation[name].permute(2, 0, 1).contiguous()