bekkalokk/kerberos: remove vendored module

hosts/bekkalokk/services/kerberos.nix

@@ -0,0 +1,14 @@
+{ config, pkgs, lib, ... }:
+{
+  security.krb5 = {
+    enable = true;
+    settings = {
+      libdefaults = {
+        default_realm = "PVV.NTNU.NO";
+        dns_lookup_realm = "yes";
+        dns_lookup_kdc = "yes";
+      };
+      realms."PVV.NTNU.NO".admin_server = "kdc.pvv.ntnu.no";
+    };
+  };
+}