nvcc fails due to -Wno-unknown-pragmas flag set in bench/CMakeLists.txt

[dqwu]

When building c-blosc2 with nvcc, the build fails due to the -Wno-unknown-pragmas flag being applied in bench/CMakeLists.txt for the sum_openmp target. nvcc does not recognize this flag, causing the build to fail with the following error:
nvc-Error-Unknown switch: -Wno-unknown-pragmas

Possible Solution

Modify bench/CMakeLists.txt to apply the -Wno-unknown-pragmas flag only when using gcc by adding the following conditional check:

if(UNIX)
    # Avoid a warning when using gcc without -fopenmp
  if(CMAKE_C_COMPILER_ID STREQUAL "GNU")
    target_compile_options(sum_openmp PRIVATE "-Wno-unknown-pragmas")
  endif()
endif()