nix/os: fix /bin activation and some cleanup

nix/os/devices/steveej-laptop/configuration.nix

@@ -1,11 +1,6 @@
 { ... }:
 
 {
-  nixpkgs.config = {
-    allowBroken = false;
-    allowUnfree = true;
-  };
-
   imports = [ 
     ../../profiles/common/configuration.nix
     ../../profiles/graphical/configuration.nix

nix/os/profiles/common/system.nix

@@ -48,6 +48,7 @@
   # Activation scripts for impure set up of paths in /
   system.activationScripts.bin = ''
     echo "setting up /bin..."
+    mkdir -p /bin
     ln -sfT ${pkgs.bash}/bin/bash /bin/.bash
     mv -Tf /bin/.bash /bin/bash
   '';