nixos/netdata: add missing dependency for syslog alarms

Netdata depends on the `logger` utility for dispatching health alarms to
syslog. This dependency was missing in the systemd units environment.

Issue: https://github.com/NixOS/nixpkgs/issues/272702
Docs: https://learn.netdata.cloud/docs/alerting/notifications/agent-dispatched-notifications/syslog
Docs, archived: https://archive.is/mkQa4

nixos/modules/services/monitoring/netdata.nix

@@ -206,7 +206,15 @@ in {
       description = "Real time performance monitoring";
       after = [ "network.target" ];
       wantedBy = [ "multi-user.target" ];
-      path = (with pkgs; [ curl gawk iproute2 which procps bash ])
+      path = (with pkgs; [
+          curl
+          gawk
+          iproute2
+          which
+          procps
+          bash
+          util-linux # provides logger command; required for syslog health alarms
+      ])
         ++ lib.optional cfg.python.enable (pkgs.python3.withPackages cfg.python.extraPackages)
         ++ lib.optional config.virtualisation.libvirtd.enable (config.virtualisation.libvirtd.package);
       environment = {