[FEA] Update to CUDA 12.9

[jakirkham]

Now that CUDA 12.9 is out and supported in RAPIDS, it should be possible for cuOpt to update from CUDA 12.8 to 12.9

Refs:

• Add CUDA 12.9 Support rapidsai/build-planning#173
• Update to CUDA 12.9.1 rapidsai/build-planning#195

[jakirkham]

Seeing references to CUDA 12.5 in this Dockerfile:

cuopt/ci/build-service.Dockerfile

Line 18 in 7441095

ARG cuda_ver=12.5.1

Also seeing references to CUDA 12.8 in the docs:

cuopt/CONTRIBUTING.md

Line 73 in 7441095

* CUDA 12.8

cuopt/docs/cuopt/source/cuopt-python/quick-start.rst

Line 17 in 7441095

pip install --extra-index-url=https://pypi.nvidia.com cuopt-cu12==25.8.* nvidia-cuda-runtime-cu12==12.8.*