m1n1: always build with chainloading support

In the past, Rust was only required for the chainloading feature,
but starting from the next m1n1 release Rust will be mandatory.
Include Rust dependencies and the chainloading feature unconditionally,
matching the upstream m1n1 release builds.

pkgs/by-name/m1/m1n1/package.nix

@@ -9,7 +9,6 @@
   nixos-icons,
   buildPackages,
   customLogo ? "${nixos-icons}/share/icons/hicolor/256x256/apps/nix-snowflake.png",
-  withChainloading ? false,
 }:
 
 let
@@ -52,8 +51,6 @@ stdenv.mkDerivation (finalAttrs: {
 
   nativeBuildInputs = [
     imagemagick
-  ]
-  ++ lib.optionals withChainloading [
     rustPackages.rustc
     rustPackages.cargo
     rustPlatform.cargoSetupHook
@@ -70,9 +67,9 @@ stdenv.mkDerivation (finalAttrs: {
   makeFlags = [
     "ARCH=${stdenv.cc.targetPrefix}"
     "RELEASE=1"
+    "CHAINLOADING=1"
   ]
-  ++ lib.optional (customLogo != null) "LOGO=custom"
-  ++ lib.optional withChainloading "CHAINLOADING=1";
+  ++ lib.optional (customLogo != null) "LOGO=custom";
 
   enableParallelBuilding = true;