[CI] SCANN Test flaky

Noticed that NEIGHBORS_ANN_SCANN_TEST failed:
Full logs here: https://github.com/NVIDIA/cuvs/actions/runs/33689912368/job/100455474437?pr=2264
Env:

• RTX Pro 6000
• CUDA 13.3.0,
• python 3.13,
• amd64
• ubuntu26.04
• latest-driver, latest-deps

[ RUN      ] ScaNN/f32_i64.build_host_input/13
/tmp/conda-bld-output/bld/rattler-build_libcuvs-headers/work/cpp/tests/neighbors/ann_scann/../ann_scann.cuh:267: Failure
Expected: (max_error) < (max_allowed_error * 1.5f), actual: 1.43570065 vs 1.425
Max reconstruction error too large: 1.4357006549835205

[  FAILED  ] ScaNN/f32_i64.build_host_input/13, where GetParam() = 80-byte object <00-10 00-00 08-00 00-00 00-00 00-00 00-00 00-40 20-00 00-00 00-00 00-00 00-10 00-00 00-00 00-00 18-00 00-00 00-00 80-3F 00-00 80-3F 02-00 00-00 08-00 00-00 00-00 00-00 00-10 00-00 00-00 00-00 0A-00 00-00 00-00 00-00 00-00 C0-7F 00-00 00-00> (61 ms)

September 9th:

https://github.com/NVIDIA/cuvs/pull/2565#issuecomment-5612135083

[ RUN      ] ScaNN/f32_i64.build_host_input/12
/tmp/conda-bld-output/bld/rattler-build_libcuvs-headers/work/cpp/tests/neighbors/ann_scann/../ann_scann.cuh:267: Failure
Expected: (max_error) < (max_allowed_error * 1.5f), actual: 1.43224525 vs 1.425
Max reconstruction error too large: 1.4322452545166016

[  FAILED  ] ScaNN/f32_i64.build_host_input/12, where GetParam() = 80-byte object <00-10 00-00 06-00 00-00 00-00 00-00 00-00 00-40 20-00 00-00 00-00 00-00 00-10 00-00 00-00 00-00 18-00 00-00 00-00 80-3F 00-00 80-3F 02-00 00-00 08-00 00-00 00-00 00-00 00-10 00-00 00-00 00-00 0A-00 00-00 00-00 00-00 00-00 C0-7F 00-00 00-00> (56 ms)

Start with cpp/tests/neighbors/ann_scann/ann_scann.cuh around line 267 and run the NEIGHBORS_ANN_SCANN_TEST using the reported environment. Compare the failing build_host_input cases and the logged max_error against max_allowed_error. Done means the test no longer flakes or the failure has a demonstrated, stable explanation.