feat: Unify all of the nixos substituters

modules/nixos/substituters.nix

@@ -0,0 +1,50 @@
+{
+  config,
+  lib,
+  ...
+}:
+with lib; let
+  cfg = config.nix.substituters;
+in {
+  options.nix.substituters = {
+    enableCuda = mkOption {
+      type = types.bool;
+      default = false;
+      description = "Enable NixOS CUDA cache";
+    };
+
+    enableLlamaCpp = mkOption {
+      type = types.bool;
+      default = false;
+      description = "Enable llama-cpp cache";
+    };
+  };
+
+  config = {
+    nix.settings = {
+      trusted-substituters =
+        [
+          "https://nix-community.cachix.org"
+          "https://nixos-raspberrypi.cachix.org"
+        ]
+        ++ optionals cfg.enableLlamaCpp [
+          "https://llama-cpp.cachix.org"
+        ]
+        ++ optionals cfg.enableCuda [
+          "https://cache.nixos-cuda.org"
+        ];
+
+      trusted-public-keys =
+        [
+          "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
+          "nixos-raspberrypi.cachix.org-1:4iMO9LXa8BqhU+Rpg6LQKiGa2lsNh/j2oiYLNOQ5sPI="
+        ]
+        ++ optionals cfg.enableLlamaCpp [
+          "llama-cpp.cachix.org-1:H75X+w83wUKTIPSO1KWy9ADUrzThyGs8P5tmAbkWhQc="
+        ]
+        ++ optionals cfg.enableCuda [
+          "cache.nixos-cuda.org:74DUi4Ye579gUqzH4ziL9IyiJBlDpMRn9MBN8oNan9M="
+        ];
+    };
+  };
+}