fix(openbao-agent): add systemctl in the PATH

Signed-off-by: Raito Bezarius <masterancpp@gmail.com>

nix/modules/openbao-agent.nix

@@ -83,8 +83,8 @@ in
           # while `vault-agent` is still stopped. This for example happens with nginx.service.
 
           stopIfChanged = false;
-          # Needs getent in PATH
+          # Needs getent and systemctl in PATH
-          path = [ pkgs.getent ];
+          path = [ pkgs.getent pkgs.systemd ];
           serviceConfig = {
             Restart = "on-failure";
             # TODO: cfg.package