Refactor secrets

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/installer/users/nick/default.nix

@@ -1,4 +1,9 @@
-{ config, lib, ... }:
+{
+  config,
+  lib,
+  inputs,
+  ...
+}:
 let
   # FIXME: https://github.com/NixOS/nixpkgs/issues/24570
   # FIXME: https://github.com/NixOS/nixpkgs/issues/305643
@@ -41,7 +46,7 @@ in
 
   # mkpasswd -s
   sops.secrets."${user}-password" = {
-    sopsFile = ../../../../secrets/personal/secrets.yaml;
+    sopsFile = "${inputs.secrets}/personal/secrets.yaml";
     key = "password";
     neededForUsers = true;
   };