### What this PR does / why we need it? Fix mypy check in CI: https://github.com/vllm-project/vllm-ascend/actions/runs/16115919385/job/45469646509?pr=1654 Mypy failed due to the greater numpy version. We need to pin `numpy=1.26.4` in vllm-ascend ### Does this PR introduce _any_ user-facing change? No ### How was this patch tested? CI passed Signed-off-by: MengqingCao <cmq0113@163.com>