nixos/netdata: remove cgroup accounting enable

cgroup accounting is enabled by default, and the option is scheduled for removal.

nixos/modules/services/monitoring/netdata.nix

···
       });
     };
 
-    systemd.enableCgroupAccounting = true;
-
     security.wrappers = {
       "apps.plugin" = {
         source = "${cfg.package}/libexec/netdata/plugins.d/apps.plugin.org";