Fix CUDA arch warning tests so they do not depend on importing the stable libtorch extension, which keeps the warning coverage active in lightweight CI environments and avoids mypy treating a fixture value as a base class.
Use regex for the compiled-arch parser, apply formatter output, and make the CUTLASS grouped GEMM Python support query fall back to false when the op is unavailable or unimplemented in the current build.
Signed-off-by: Shengqi Chen <harry-chen@outlook.com>