deven v1.6 ignores allowUnfree in devenv.yaml or in system config

[dz0ny]

Describe the bug
devenv ignores allowUnfree in devenv.yaml or in system config. When trying to configure the MongoDB service, it fails to build due to allowUnfree not being set. However, both are set in the system and in devenv.yaml.

To reproduce
https://github.com/teamniteo/devenv-broken-alllow-unfree/actions/runs/14904061804

error: Package ‘mongodb-ce-8.0.4’ in «github:cachix/devenv-nixpkgs/fbc071e5c11e23fba50037de37268e3d8a1858eb»/pkgs/by-name/mo/mongodb-ce/package.nix:121 has an unfree license (‘SSPL’), refusing to evaluate.

       a) To temporarily allow unfree packages, you can use an environment variable
          for a single invocation of the nix tools.

            $ export NIXPKGS_ALLOW_UNFREE=1

          Note: When using `nix shell`, `nix build`, `nix develop`, etc with a flake,
                then pass `--impure` in order to allow use of environment variables.

       b) For `nixos-rebuild` you can set
         { nixpkgs.config.allowUnfree = true; }
       in configuration.nix to override this.

       Alternatively you can configure a predicate to allow specific packages:
         { nixpkgs.config.allowUnfreePredicate = pkg: builtins.elem (lib.getName pkg) [
             "mongodb-ce"
           ];
         }

       c) For `nix-env`, `nix-build`, `nix-shell` or any other Nix command you can add
         { allowUnfree = true; }
       to ~/.config/nixpkgs/config.nix.

Version

devenv version
devenv 1.6.0 (aarch64-darwin)

[clotodex]

#1854 etc - update your devenv (dont know how you installed it). The version does not change but there was a fix pushed right after.
@dz0ny if you installed via nix, a simple upgrade should do the trick

(@domenkozar, imh(umble)o a 1.6.1 push might have helped - or still will help - with this issue being reported over and over again.)

[sandydoo]

If you encounter this issue, update nixpkgs to get a working version of v1.6.

I've also cut a new v1.6.1 release to make the patch more visible.