[tests] fix import.

[sayakpaul]

What does this PR do?

Not really sure how it was passed.

[sayakpaul]

Should be a simple import change. Merging.

[yao-matrix]

@sayakpaul the reason is:
In PR #11085, new TorchCompileTesterMixin cases were added w/ require_torch_gpu not not merged.
Later PR #11406 was submitted to enable all gpu only cases to work on XPU, so using require_torch_accelerator and remove require_torch_gpu per ruff since it's not referenced anymore.

But there is a time gap btw these 2 cases merging(2 hours) and it's no conflict btw these PRs, since the later PR didn't change TorchCompileTesterMixin(even not aware of it), and static diff tool cannot detect such situation, since it's a runtime dependency loss.