Migrate to flakes

configuration.nix

@@ -36,7 +36,7 @@
     timeout = 3;
   };
 
-  # Run Nix garbage collector, while avoiding compiling
+  # Run Nix garbage collector and enable flakes
   nix = {
     autoOptimiseStore = true;
     gc = {
@@ -48,7 +48,9 @@
       keep-outputs = true
       keep-derivations = true
       gc-keep-outputs = true
+      experimental-features = nix-command flakes
     '';
+    package = pkgs.nixUnstable;
   };
 
   # Clean tmp directory on shutdown
@@ -100,7 +102,6 @@
 
   # Import other configuration modules
   imports = [
-    <nixpkgs/nixos/modules/services/hardware/sane_extra_backends/brscan4.nix>
     ./modules/hardware-configuration.nix
     ./modules/software.nix
     ./modules/networking.nix