remove dead binfmt code

hosts/common/hardware/default.nix

@@ -79,11 +79,6 @@
     HandleLidSwitch=lock
   '';
 
-  # some packages build only if binfmt *isn't* present
-  nix.settings.system-features = lib.mkIf (config.boot.binfmt.emulatedSystems == []) [
-    "no-binfmt"
-  ];
-
   # services.snapper.configs = {
   #   root = {
   #     subvolume = "/";

hosts/modules/nixcache.nix

@@ -91,7 +91,6 @@ in
         speedFactor = 2;
         supportedFeatures = [
           # "big-parallel"  # it can't reliably build webkitgtk
-          "no-binfmt"
         ];
         mandatoryFeatures = [ ];
         sshUser = "nixremote";

hosts/modules/roles/build-machine.nix

@@ -11,10 +11,6 @@ in
       type = types.bool;
       default = false;
     };
-    emulation = mkOption {
-      type = types.bool;
-      default = false;
-    };
     ccache = mkOption {
       type = types.bool;
       default = false;
@@ -37,13 +33,6 @@ in
 
       nix.settings.system-features = [ "big-parallel" ];
 
-      # enable cross compilation
-      # TODO: do this via stdenv injection, linking into /run/binfmt the stuff in <nixpkgs:nixos/modules/system/boot/binfmt.nix>
-      boot.binfmt.emulatedSystems = lib.optionals cfg.emulation [
-        "aarch64-linux"
-        # "aarch64-darwin"  # not supported
-        # "x86_64-darwin"   # not supported
-      ];
       # corresponds to env var: NIXPKGS_ALLOW_UNSUPPORTED_SYSTEM=1
       # nixpkgs.config.allowUnsupportedSystem = true;
     })