Use gnu compilers for `smart build` even if using NVIDIA compilers for smartredis and cfd solver

[soaringxmc]

We should use gnu compilers when smart build --device cpu to build smartsim dependencies (RedisAI and ML-package backends) even if nvidia compilers are used for
make lib-with-fortran CC=nvc CXX=nvc++ FC=nvfortran, smartredis-mpi and CFD solver

Check the note here
GPU builds can be troublesome due to the way that RedisAI and the ML-package backends look for the CUDA Toolkit and cuDNN libraries. Please see the [Platform Installation Section]