bug#51889: changing focus to Chromium can crash Sway entirely

["bdju" via Bug reports for GNU Guix <bug-guix@gnu.org>]

guix (GNU Guix) 33a80e111096b05af3d60576dfcb2d67099dc60e
Guix System

For the second time now, when focusing the chromium window, Sway has
entirely crashed. I'm using ungoogled-chromium-wayland.

I have the following lines in my Sway config:

```
    # focus browser (chromium)
    bindsym ctrl+Shift+$mod+b [app_id="chromium-browser"] focus
```

So, I pressed those keys to jump right to it, then my monitors went
black and everything disappeared. I believe last time this happened,
I hadn't made that keybind yet, but I was similarly using a script to
focus chromium by its app_id with a swaymsg command before.
Chromium had some coursera tabs open. The first time there was likely
a paused video. I don't think I had a video up this time. (I am using
Chromium exclusively for coursera stuff recently because audio is broken
in qutebrowser and if I watch the lectures in mpv+youtube-dl I lose the
feature of being able to click part of the transcipt to jump to that
part of the video. Also, I have to let the video play in a browser
anyway so the task gets marked as complete.)

I'm not sure if this will be at all easy to reproduce. I jumped to the
Chromium window dozens of times without crashing all of Sway before, so
some special situation must have to happen. I had another video open in
mpv, some chat programs open, and qutebrowser at the time. I wasn't in
danger of running out of RAM the last time I'd looked. I think CPU
usage was normal.