Move zerotier out of the common module

modules/common.nix

@@ -1,4 +1,4 @@
-{ pkgs, secrets, ... }:
+{ pkgs, ... }:
 {
   nixpkgs.config.allowUnfree = true;
 
@@ -41,11 +41,6 @@
     '';
   };
 
-  services.zerotierone = {
-    enable = true;
-    joinNetworks = secrets.zerotier.networks;
-  };
-
   environment.systemPackages = with pkgs; [
     git-crypt
     jq

modules/zerotier.nix

@@ -0,0 +1,7 @@
+{ secrets, ... }:
+{
+  services.zerotierone = {
+    enable = true;
+    joinNetworks = secrets.zerotier.networks;
+  };
+}