feat(utils): add support for Intel XPU backend (#2233)

* feat: add support for Intel XPU backend in device selection

* Update src/lerobot/utils/utils.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Signed-off-by: Lim Xiang Yang <xiangyang95@gmail.com>

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* fix: update is_amp_available to include xpu as a valid device

* Update src/lerobot/utils/utils.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Signed-off-by: Lim Xiang Yang <xiangyang95@gmail.com>

* Update src/lerobot/utils/utils.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Signed-off-by: Lim Xiang Yang <xiangyang95@gmail.com>

* fix: remove unused return and add comments on fp64 fallback handling

* fix(utils): return dtype in case xpu has fp64

---------

Signed-off-by: Lim Xiang Yang <xiangyang95@gmail.com>
Co-authored-by: Lim, Xiang Yang <xiang.yang.lim@intel.com>
Co-authored-by: Lim Xiang Yang <xiangyang95@gmail.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Jade Choghari <chogharijade@gmail.com>

tests/async_inference/test_helpers.py

@@ -389,7 +389,7 @@ def test_raw_observation_to_observation_device_handling():
     # Check that all expected keys produce tensors (device placement handled by preprocessor later)
     for key, value in observation.items():
         if isinstance(value, torch.Tensor):
-            assert value.device.type in ["cpu", "cuda", "mps"], f"Tensor {key} on unexpected device"
+            assert value.device.type in ["cpu", "cuda", "mps", "xpu"], f"Tensor {key} on unexpected device"
 
 
 def test_raw_observation_to_observation_deterministic():