Lim, Thing-han

Results 2 issues of Lim, Thing-han

This PR mainly tried to remove the dependency of nix-shell-action and make use of the `shell` feature provided by github action - **ci: add nix setup composite action** - **ci:...

This PR uses the latest available instructions like #spill, #unspill, #spill_to_mmx, and make the FrodoKem reference implementation pass the SCT check. The implementation is also refactored into indcpa and kem...