Bump nix from 0.13.0 to 0.20.2 in /lib#5

dependabot[bot] wants to merge 1 commit intomasterpolaris64/syswall:masterfrom

dependabot/cargo/lib/nix-0.20.2polaris64/syswall:dependabot/cargo/lib/nix-0.20.2Copy head branch name to clipboard