fix: remove incus-admin group references from user configs

- Remove incus-admin group from geir and sma users
- Fixes deployment issue where cowsql was being built despite incus being disabled
- Addresses congenital-optimist build failure

modules/users/geir.nix

@@ -20,7 +20,6 @@ in {
       "wheel"
       "networkmanager"
       "libvirt"
-      "incus-admin"
       "podman"
       "audio"
       "video"

modules/users/sma.nix

@@ -21,7 +21,6 @@
       "wheel" # sudo access
       "networkmanager" # network management
       "libvirt" # virtualization management
-      "incus-admin" # container management
       "podman" # container runtime
       "docker" # docker compatibility (if needed)
       "media" # shared media access for NFS shares