Hello,

Lock does not work anymore on XFCE 4.20, after moving from 4.18.
When I try to run the command manually via the terminal on XFCE 4.20, this
is what I get:

```console
$ xflock4
/gnu/store/yz669dvm1cm9nqcxkm8hq8zzgf0cy96f-profile/bin/xflock4: line 52:
gdbus: command not found
```
This must be because of the introduction of commit 42db188a
<https://gitlab.xfce.org/xfce/xfce4-session/-/commit/42db188a912413d099150dd9f44f008285c8a493>
somewhere around 4.19, making xflock4 dependent on D-Bus.

Regards,
Ashvith