pass /etc/nixos folder as an input to override

This way it is expected to have access to this path from build results,
making it possible to reproduce the build.

flake.lock

@@ -1,18 +1,5 @@
 {
   "nodes": {
-    "hardware-configuration-nix": {
-      "flake": false,
-      "locked": {
-        "lastModified": 1692731346,
-        "narHash": "sha256-rQIpYKwowqbbVVurEl5qNpuPfoRyEUMefoZXrUoO6p8=",
-        "path": "hardware-configuration.nix",
-        "type": "path"
-      },
-      "original": {
-        "id": "hardware-configuration-nix",
-        "type": "indirect"
-      }
-    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1686476475,
@@ -30,10 +17,8 @@
     },
     "root": {
       "inputs": {
-        "hardware-configuration-nix": "hardware-configuration-nix",
         "nixpkgs": "nixpkgs",
-        "selfprivacy-overlay": "selfprivacy-overlay",
+        "selfprivacy-overlay": "selfprivacy-overlay"
-        "userdata-json": "userdata-json"
       }
     },
     "selfprivacy-overlay": {
@@ -50,19 +35,6 @@
         "type": "git",
         "url": "https://git.selfprivacy.org/SelfPrivacy/selfprivacy-nix-repo.git"
       }
-    },
-    "userdata-json": {
-      "flake": false,
-      "locked": {
-        "lastModified": 1689259484,
-        "narHash": "sha256-Co3QGsxCjDspP5Nzzu1zICkee5CEq+ORlxSF3bFqbCY=",
-        "path": "userdata/userdata.json",
-        "type": "path"
-      },
-      "original": {
-        "id": "userdata-json",
-        "type": "indirect"
-      }
     }
   },
   "root": "root",

flake.nix

@@ -7,23 +7,21 @@
     selfprivacy-overlay.url =
       "git+https://git.selfprivacy.org/SelfPrivacy/selfprivacy-nix-repo.git";
 
-    # these inputs are expected to be set by the caller
+    # the /etc/nixos folder input is expected to be set by the caller
     # for example, upon nix build using --override-input
-    userdata-json.flake = false; # userdata.json
+    etc-nixos.flake = false;
-    hardware-configuration-nix.flake = false; # hardware-configuration.nix
   };
 
   outputs =
     { self
+    , etc-nixos
     , nixpkgs
     , selfprivacy-overlay
-    , userdata-json
-    , hardware-configuration-nix
     }:
     let
       system = "x86_64-linux";
-      userdata = builtins.fromJSON (builtins.readFile userdata-json);
+      userdata =
-      hardware-configuration = import hardware-configuration-nix;
+        builtins.fromJSON (builtins.readFile "${etc-nixos}/userdata.json");
     in
     {
       nixosConfigurations = {
@@ -33,7 +31,7 @@
             # SelfPrivacy overlay
             { nixpkgs.overlays = [ selfprivacy-overlay.overlay ]; }
             # machine specifics
-            hardware-configuration
+            "${etc-nixos}/hardware-configuration.nix"
             # main configuration part
             ./configuration.nix
           ];