Restructure flake.nix for a simpler config for building different images off the same NixOS config.

nix/configuration/roles/amd_s2idle/default.nix

@@ -17,31 +17,27 @@
     };
   };
 
-  config = lib.mkIf config.me.amd_s2idle.enable (
-    lib.mkMerge [
-      {
-        environment.systemPackages = with pkgs; [
-          amd-debug-tools
-        ];
-        nixpkgs.overlays = [
-          (
-            final: prev:
-            let
-              innerPackage = (final.callPackage ./package.nix { });
-            in
-            {
-              amd-debug-tools = innerPackage;
-            }
-          )
-          (final: prev: {
-            pythonPackagesExtensions = prev.pythonPackagesExtensions ++ [
-              (python-final: python-prev: {
-                cysystemd = (python-final.callPackage ./cysystemd.nix { });
-              })
-            ];
+  config = lib.mkIf config.me.amd_s2idle.enable {
+    environment.systemPackages = with pkgs; [
+      amd-debug-tools
+    ];
+    nixpkgs.overlays = [
+      (
+        final: prev:
+        let
+          innerPackage = (final.callPackage ./package.nix { });
+        in
+        {
+          amd-debug-tools = innerPackage;
+        }
+      )
+      (final: prev: {
+        pythonPackagesExtensions = prev.pythonPackagesExtensions ++ [
+          (python-final: python-prev: {
+            cysystemd = (python-final.callPackage ./cysystemd.nix { });
           })
         ];
-      }
-    ]
-  );
+      })
+    ];
+  };
 }