Explicitly initialize with zmm_vector<uint64_t> for arg methods on macOS

[r-devulap]

For some reason, macOS clang-15++ does not like zmm_vector<arrsize_t> and it fails with:

../numpy/_core/src/npysort/x86-simd-sort/src/avx512-common-argsort.h:18:27: error: implicit instantiation of undefined template 'zmm_vector<unsigned long>'
using argreg_t = typename argtype::reg_t;
                          ^
../numpy/_core/src/npysort/x86-simd-sort/src/avx512-common-qsort.h:111:8: note: template is declared here
struct zmm_vector;