Arch Linux

Description:

Package `xpra` shows no systray icon on KDE on Wayland. This seems to be specific to arch and derivatives from https://github.com/Xpra-org/xpra/issues/3789


Additional info:
* package version(s): 4.4.5-1
* config and/or log files etc
logging with `xpra -d tray attach ssh:<host>:<display>` you get

```
2023-09-04 18:39:46,008 cannot load appindicator tray
Traceback (most recent call last):
File "/usr/lib/python3.11/site-packages/xpra/platform/xposix/gui.py", line 128, in get_native_tray_classes
from xpra.platform.xposix.appindicator_tray import AppindicatorTray
File "/usr/lib/python3.11/site-packages/xpra/platform/xposix/appindicator_tray.py", line 27, in <module>
gi.require_version("AyatanaAppIndicator3", "0.1") # @UndefinedVariable
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.11/site-packages/gi/__init__.py", line 126, in require_version
raise ValueError('Namespace %s not available' % namespace)
ValueError: Namespace AyatanaAppIndicator3 not available
2023-09-04 18:39:46,008 Warning: appindicator library not found
2023-09-04 18:39:46,008 you may want to install libappindicator
2023-09-04 18:39:46,009 to enable the system tray.
```
You do not get this on X11.

* link to upstream bug report, if any: https://github.com/Xpra-org/xpra/issues/3789. Bug is closed there: issue appears to be now specific to arch and derivatives.

Steps to reproduce:

- start xpra with `xpra attach ssh:<host>:<display>` where `<host>` and `<display>` correspond to a running xpra server.