tinc: remove unnecessary networking.interfaces

This breaks with networking backends enabled and
also creates large delays on boot when some services depends
on the network target. It is also not really required
because tinc does create those interfaces itself.

fixes #27070

(cherry picked from commit 5a1f0f9aa3)

nixos/modules/services/networking/tinc.nix

@@ -148,14 +148,6 @@ in
         }
       ));
 
-    networking.interfaces = flip mapAttrs' cfg.networks (network: data: nameValuePair
-      ("tinc.${network}")
-      ({
-        virtual = true;
-        virtualType = "${data.interfaceType}";
-      })
-    );
-
     systemd.services = flip mapAttrs' cfg.networks (network: data: nameValuePair
       ("tinc.${network}")
       ({