[safetensors] don't use in `torch<1.10`
`safetensors` only seems to work with pt>=1.10. This PR fixes this breakage:

```
python -c 'import sys; from transformers import AutoModel; AutoModel.from_pretrained(sys.argv[1])'  "bigscience/bigscience-small-testing"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/mnt/nvme0/code/huggingface/transformers-master/src/transformers/models/auto/auto_factory.py", line 471, in from_pretrained
    return model_class.from_pretrained(
  File "/mnt/nvme0/code/huggingface/transformers-master/src/transformers/modeling_utils.py", line 2424, in from_pretrained
    state_dict = load_state_dict(resolved_archive_file)
  File "/mnt/nvme0/code/huggingface/transformers-master/src/transformers/modeling_utils.py", line 413, in load_state_dict
    return safe_load_file(checkpoint_file)
  File "/home/stas/anaconda3/envs/py38-pt19/lib/python3.8/site-packages/safetensors/torch.py", line 101, in load_file
    result[k] = f.get_tensor(k)
AttributeError: module 'torch' has no attribute 'frombuffer'
```
_The documentation is not available anymore as the PR was closed or merged._<|||||>I need a PR merged to test my fix for the torch and tf run which is broken on main (but the fix itself does not trigger any tests). This one seems a good candidate so merging now and will keep an eye on the test :-) <|||||>Shouldn't those be fixed in safetensors instead? ie here https://github.com/huggingface/safetensors/blob/5c1d366813e46c6f9f2c71aa8b89e0c916a92b2f/bindings/python/setup.py#L23 ?<|||||>Can be both :)<|||||>Also, I left torch version out on purpose at the time, as I wasn't sure about the support policy and wether or not supporting older version was worth the effort (since they require a lot more handling from safetensors itself).