fix: use cnrtMemcpyAsync_V2 for Cambricon async copies

[spike-zhu]

Summary

• Update Cambricon MemcpyAsync in src/native/cambricon/runtime_.h to use cnrtMemcpyAsync_V2.
• Remove the unused <type_traits> dependency after eliminating runtime signature dispatch.

Motivation

After InfiniCore switched its Cambricon runtime implementation to InfiniRT,
InfiniLM inference failed during queue synchronization with:

CN_ERROR_INVALID_ADDRESS
cnrtQueueSync: MLU queue sync failed

Type of Change

• feat - new feature / new backend capability / new public API
• fix - bug fix
• perf - performance improvement without behavior 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)
• Hygon (WITH_HYGON)
• MetaX (WITH_METAX)
• Moore (WITH_MOORE)
• Cambricon (WITH_CAMBRICON)
• Ascend (WITH_ASCEND)
• Build system / CMake / generated headers
• Public headers / installed consumer API
• Documentation only

Smoke Build and Test Result

Test Results on Supported Platforms

Platform	Affected	Build / Smoke Result	Full Result / Notes
CPU
NVIDIA
Iluvatar
Hygon
MetaX
Moore
Cambricon
Ascend

Full `ctest` output (optional)

paste here

Benchmark / Performance Impact

Notes for Reviewers

InfiniLM 测试截图：

修改前

修改后