Raising the baseline for the `nvptx64-nvidia-cuda` target

The nvptx64-nvidia-cuda target is a compilation target for NVIDIA GPUs. When using this target, the final output is PTX . Two version choices shape that output: a GPU architecture (for example, sm_70 , sm_80 , …), which determines which GPUs can run the PTX, and a PTX ISA version, which determines which CUDA driver versions can load (and JIT-compile) the PTX. In Rust 1.97 (scheduled for release on July 9, 2026), the baseline PTX ISA version and GPU architecture for nvptx64-nvidia-cuda will be increased . Th