test(tensorscatter): cover circular prefix preservation (#32264)
### Description
Adds a `TensorScatter` circular-mode regression test where the batch
dimension exceeds the maximum sequence length. The case also wraps
sequence writes from slot 3 to slot 0, verifying that modulo applies
only to the sequence coordinate while every batch prefix remains
unchanged.
### Motivation and Context
onnx/onnx#8353 identified that applying modulo to every coordinate in
the full index tuple can fold one batch into another. ONNX Runtime's CPU
and CUDA kernels already preserve prefix coordinates, but the existing
tests use prefix dimensions smaller than the maximum sequence length and
cannot distinguish the incorrect behavior.
This test makes the regression observable: with `batch_size=5` and
`max_sequence_length=4`, a full-tuple modulo maps batch 4 to batch 0.
Related: onnx/onnx#8353
### Testing
- `cmake --build build/cpu_only/Debug --target onnxruntime_provider_test
--parallel`
- `./onnxruntime_provider_test
--gtest_filter=TensorScatterTest.Circular_BatchLargerThanMaxSequenceLength`
- `./onnxruntime_provider_test --gtest_filter=TensorScatterTest.*` (23
passed)
- `lintrunner
onnxruntime/test/providers/cpu/llm/tensorscatter_op_test.cc`
Signed-off-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Copilot-Session: 427bc0f4-eaf2-406e-95ad-b5b1af6ccdc6