logrotate: use systemd instead of cron

nixos/modules/services/logging/logrotate.nix

@@ -8,10 +8,6 @@ let
   configFile = pkgs.writeText "logrotate.conf"
     cfg.config;
 
-  cronJob = ''
-    5 * * * * root ${pkgs.logrotate}/sbin/logrotate ${configFile}
-  '';
-
 in
 {
   options = {
@@ -33,6 +29,16 @@ in
   };
 
   config = mkIf cfg.enable {
-    services.cron.systemCronJobs = [ cronJob ];
+    systemd.services.logrotate = {
+      description   = "Logrotate Service";
+      wantedBy      = [ "multi-user.target" ];
+      startAt       = "*-*-* *:05:00";
+
+      serviceConfig.Restart = "no";
+      serviceConfig.User    = "root";
+      script = ''
+        exec ${pkgs.logrotate}/sbin/logrotate ${configFile}
+      '';
+    };
   };
 }