feat: add support for make codegen/pre-commit through nix

[isubasinghe]

NOTE: You need to be inside a nix shell for this to work, use nix develop to get a shell.

Adds support for make codegen, make pre-commit -B commands via nix.
To use nix supply the USE_NIX variable with true when invoking make.
For example make USE_NIX=true pre-commit -B

[isubasinghe]

@JPZ13 can you have a suss at this, should be trivial ? Can't assign you myself.

[JPZ13]

@isubasinghe - pardon the permissions issue. You should now be a maintainer on the repo

I'm also a little strapped for time at the moment. Could you get @Joibel or @rohankmr414 to test it out?

[isubasinghe]

@JPZ13 ah no worries, I will ask @Joibel