[Installation] limit opencv-python-headless version to resolve numpy version conflict (#3713)

### What this PR does / why we need it?

vllm requires opencv-python-headless >= 4.11.0 which requires
(numpy<2.3.0,>=2), but vllm-ascend numpy version must be less than
2.0.0, so limit opencv-python-headless less than 4.11.0.86 will fix this
conflict.

### How was this patch tested?

tested by CI 

- vLLM version: v0.11.0rc3
- vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.0

Signed-off-by: 22dimensions <waitingwind@foxmail.com>

pyproject.toml

@@ -21,6 +21,7 @@ requires = [
     "msgpack",
     "quart",
     "numba",
+    "opencv-python-headless<=4.11.0.86", # Required to avoid numpy version conflict with vllm
 ]
 build-backend = "setuptools.build_meta"
 

requirements.txt

@@ -15,6 +15,7 @@ torch>=2.7.1
 torchvision
 wheel
 pandas-stubs
+opencv-python-headless<=4.11.0.86 # Required to avoid numpy version conflict with vllm
 
 # requirements for disaggregated prefill
 msgpack