[tests] use `torch_device` instead of `auto` for model testing (#29531)
* use torch_device
* skip for XPU
* Update tests/generation/test_utils.py
Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>
---------
Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>