systemd: sanitize /etc/group and gids

sgx group was added in systemd-248 in commit
- c9c4899f44

Fixes warnings at boot by: systemd-udevd and dbus-daemon at boot:
  ~ # journalctl | grep Unknown
  systemd-udevd[525]: /usr/lib/udev/rules.d/50-udev-default.rules:56 Unknown group 'sgx', ignoring.
  systemd-udevd[525]: /usr/lib/udev/rules.d/50-udev-default.rules:57 Unknown group 'sgx', ignoring.
  dbus-daemon[568]: dbus[568]: Unknown group "wheel" in message bus configuration file
  dbus-daemon[568]: dbus[568]: Unknown username "systemd-oom" in message bus configuration file

renumber gids:
- input 199 -> 104
- kvm 10 -> 36
- render 12 -> 105

ref:
- 9a797ddc41
- https://pagure.io/setup/blob/master/f/uidgid

packages/sysutils/systemd/package.mk

@@ -273,20 +273,26 @@ post_install() {
   add_group systemd-network 193
   add_user systemd-network x 193 193 "systemd-network" "/" "/bin/sh"
 
-  add_group audio 63 pipewire
+  add_group systemd-oom 194
+  add_user systemd-oom x 194 194 "systemd Userspace OOM Killer" "/" "/bin/false"
+
+  add_group adm 4
+  add_group tty 5
+  add_group disk 6
+  add_group lp 7
+  add_group kmem 9
+  add_group wheel 10
   add_group cdrom 11
   add_group dialout 18
-  add_group disk 6
   add_group floppy 19
-  add_group kmem 9
-  add_group kvm 10
-  add_group lp 7
-  add_group render 12
-  add_group tape 33
-  add_group tty 5
-  add_group video 39 pipewire
   add_group utmp 22
-  add_group input 199
+  add_group tape 33
+  add_group kvm 36
+  add_group video 39 pipewire
+  add_group audio 63 pipewire
+  add_group input 104
+  add_group render 105
+  add_group sgx 106
 
   enable_service machine-id.service
   enable_service debugconfig.service