env bash is all well and good for normies, but if you're already on NixOS did you know you can have nix-shell be your interpreter and back flip into any reproducible interpreted environment you like?
Or any other system with Nix installed. I use this at work to provide scripts with all their dependencies specified that work across any Linux distro & MacOS. First execution is slow since it has to fetch everything, but after that it's fast and just works.
https://nixos.wiki/wiki/Nix-shell_shebang