move unfree allow list to default.nix

modules/nix/default.nix

@@ -10,4 +10,14 @@
   # Timzone and locales (same for all machines so I put it here)
   i18n.defaultLocale = "en_US.UTF-8";
   time.timeZone = "Europe/Paris";
+
+  nixpkgs.config.allowUnfreePredicate = pkg: builtins.elem (lib.getName pkg) [
+    "steam"
+    "steam-original"
+    "steam-unwrapped"
+    "steam-run"
+    "obsidian"
+    "nvidia-x11"
+    "nvidia-settings"
+  ];
 }