Triton test failed in CI: ImportError: cannot import name 'AttrsDescriptor'

[tengyifei]

See https://github.com/pytorch/xla/actions/runs/13799623710/job/38601675184?pr=8807

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ERROR: test_gpu_custom_call_triton_add (__main__.TritonTest)
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Traceback (most recent call last):
  File "/__w/xla/xla/pytorch/xla/test/test_triton.py", line 256, in test_gpu_custom_call_triton_add
    payload = xla_triton.triton_call(
  File "/usr/local/lib/python3.10/site-packages/torch_xla/experimental/triton.py", line 211, in triton_call
    return triton_kernel_call_lowering(array_args, kernel, compiled_kernel,
  File "/usr/local/lib/python3.10/site-packages/torch_xla/experimental/triton.py", line 142, in triton_kernel_call_lowering
    from triton.backends.compiler import AttrsDescriptor
ImportError: cannot import name 'AttrsDescriptor' from 'triton.backends.compiler' (/usr/local/lib/python3.10/site-packages/triton/backends/compiler.py)

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ERROR: test_gpu_custom_call_triton_flash_attention (__main__.TritonTest)
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Traceback (most recent call last):
  File "/__w/xla/xla/pytorch/xla/test/test_triton.py", line 292, in test_gpu_custom_call_triton_flash_attention
    payload = xla_triton.triton_call(
  File "/usr/local/lib/python3.10/site-packages/torch_xla/experimental/triton.py", line 211, in triton_call
    return triton_kernel_call_lowering(array_args, kernel, compiled_kernel,
  File "/usr/local/lib/python3.10/site-packages/torch_xla/experimental/triton.py", line 142, in triton_kernel_call_lowering
    from triton.backends.compiler import AttrsDescriptor
ImportError: cannot import name 'AttrsDescriptor' from 'triton.backends.compiler' (/usr/local/lib/python3.10/site-packages/triton/backends/compiler.py)

[ysiraichi]

Apparently, this was caused by a triton pin update inside PyTorch pytorch/pytorch#148971. This wouldn't have happened if we did have a PyTorch pin, though. Somewhat related to #8745.