CRIU currently requires a number of dependencies in order to build from
source. The package names vary across distributions and package
managers. A Nix flake allows developers to spin up a dev environment
with `nix develop`, eliminating the hassle of manual dependency
management. It also prevents polluting the global package set on the
machine.
Signed-off-by: Prajwal S N <prajwalnadig21@gmail.com>