Enhance `nd_item` code coverage in CI validation.

During code review of https://github.com/intel/llvm/pull/12236, we found that `nd_item::get_nd_range()` is not covered by pre-commit tests. I think only Khronos SYCL CTS covers all `nd_item` methods, but unfortunately, intel/llvm CI doesn't run these tests.

I suggest we add a short "smoke" test to validate `nd_item::get_nd_range()` methods and other `nd_item` methods not covered by existing CI validation.