ci: use Ascend 910C post4 CI image

[baominghelly]

Summary

• Reuse the validated Ascend 910C image infiniops-ci/ascend:cann9.1.0-torch2.10.0-npu-post4-20260909 through skip_build and source_image instead of rebuilding the legacy Ascend image.
• Keep the existing Ascend runner label, -j$(nproc) build parallelism, and current InfiniOps SoC auto-detection behavior.
• Update both the reusable workflow ref and ci_ref to 901566229509ac54f520210c6856bf163209f907, which includes Ascend dual-chip physical-ID parsing on top of the existing CI execution line.

Motivation

The current Ascend CI image does not provide the validated torch_npu 2.10.0.post4 environment required by the current Ascend PyTorch backend. Reusing the prepared post4 image makes the build environment deterministic and avoids rebuilding a large image on every CI run.

The two CI references are updated together so the reusable workflow and the checked-out .ci tooling come from the same revision.

Type of Change

• feat — new feature / new operator / new platform
• fix — bug fix
• perf — performance improvement (no behavioral change)
• refactor — code restructuring without behavior change
• test — adding or fixing tests only
• docs — documentation only
• build / ci — build system or CI configuration
• chore — tooling, formatting, or other non-code changes
• Breaking change (requires a ! in the Conventional Commits prefix or a BREAKING CHANGE: footer)

Platforms Affected

• CPU (WITH_CPU)
• NVIDIA (WITH_NVIDIA)
• Iluvatar (WITH_ILUVATAR)
• MetaX (WITH_METAX)
• Cambricon (WITH_CAMBRICON)
• Moore (WITH_MOORE)
• Ascend (WITH_ASCEND)
• PyTorch C++ bindings (WITH_TORCH)
• Build system / CMake / CI
• Python bindings / user-facing API

The platform checkboxes acknowledge that changing the reusable workflow revision can affect orchestration for every configured platform. The image-selection change itself is Ascend-specific.

Smoke Test Result

Validated the final configuration locally and in GitHub Actions on Ascend 910C:

PYTHONDONTWRITEBYTECODE=1 python3 .ci/run.py \
  --config .github/ci_config.yml \
  --job npu \
  --local \
  --image-tag df-4196b1fe7209 \
  --results-dir "$ROOT/local-results"

Trimmed result:

InfiniRT build: passed
InfiniOps wheel build: passed
136 passed, 43 skipped, 28 warnings in 16.76s

The GitHub Actions Ascend job on runner Ascend-910C-Server-000 also completed successfully with the same result. Generated Docker arguments were checked for:

ASCEND_VISIBLE_DEVICES=0
--device=/dev/davinci1:/dev/davinci0
--memory 32g
--shm-size 16g

Test Results on Supported Platforms

Platform	Affected	Build / Smoke Result	Full Result / Notes
NVIDIA	Potential	In progress in GitHub Actions	Global reusable workflow ref changes; platform-specific config is unchanged
Iluvatar	Potential	In progress in GitHub Actions	Global reusable workflow ref changes; platform-specific config is unchanged
MetaX	Potential	Failed during InfiniOps wheel build	Under investigation; platform-specific config is unchanged
Cambricon	Potential	In progress in GitHub Actions	Global reusable workflow ref changes; platform-specific config is unchanged
Moore	Potential	Queued in GitHub Actions	Global reusable workflow ref changes; platform-specific config is unchanged
Ascend	Yes	smoke passed locally and in GitHub Actions	136 passed, 43 skipped; JUnit reported zero failures and errors

Additional required checks at the current head:

Ruff: success
Clang Format: success

Full `pytest` output (optional)

Not run - full suite deferred; this Draft PR changes CI orchestration and image selection, not operator implementations.

Benchmark / Performance Impact

N/A

Notes for Reviewers

• The post4 image is currently local to the prepared 910C runner machines. Before enabling this on every Ascend runner, that runner must either have the image loaded or the image must be published to an internal registry.
• runner_label intentionally remains Ascend; temporary runner availability may need to be managed during rollout so jobs do not land on runners without the post4 image.
• -j$(nproc) and SoC auto-detection are intentionally unchanged.
• 901566229509ac54f520210c6856bf163209f907 is the current stacked CI revision used for validation. Once the underlying CI branch reaches InfiniTensor/ci master, these references can be updated to the final master SHA in a follow-up CI-only change.
• YAML parsing and git diff --check passed for the final configuration.