flake: nixComponents_2_33 removed from nixpkgs, build fails against nixComponents_2_34

`nixComponents_2_33` was removed from nixpkgs in [nixos/nixpkgs#505787](https://github.com/NixOS/nixpkgs/pull/505787). The nixos-unstable channel has already advanced past this point, so the next flake update will fail. This also breaks for consumers right now using the flake overlay with `inputs.nixpkgs.follows`. Bumping to `nixComponents_2_34` also seems to require a source fix. Based on my very amateur testing, it looks like `Value::type(bool)` became `Value::type<bool>()` in nix 2.34.