nixos/pgadmin: Apply more hardening settings (#449299)

        User = "pgadmin";

        DynamicUser = true;

        LogsDirectory = "pgadmin";

        LogsDirectoryMode = "750";

        StateDirectory = "pgadmin";

        StateDirectoryMode = "750";

        ExecStart = "${cfg.package}/bin/pgadmin4";

        LoadCredential = [

          "initial_password:${cfg.initialPasswordFile}"

        CapabilityBoundingSet = "";

        LockPersonality = true;

        MemoryDenyWriteExecute = true;

        MountAPIVFS = true;

        NoNewPrivileges = true;

        PrivateDevices = true;

        PrivateMounts = true;

        PrivateTmp = true;

        PrivateUsers = true;

        ProtectClock = true;

        ProtectControlGroups = true;

        ProtectControlGroups = "strict";

        ProtectHome = true;

        ProtectHostname = true;

        ProtectKernelLogs = true;

        ProtectKernelModules = true;

        ProtectKernelTunables = true;

        ProtectProc = "invisible";

        ProtectSystem = "full";

        RemoveIPC = true;

        RestrictAddressFamilies = [