"the Tails desktop is ready" step is fragile due to buggy display of Florence systray icon
Video attached. This breaks “the Tails desktop is ready” and in turn “Tails seems to have booted normally”. Of course we cannot mark this step as fragile. How about we try waiting for another systray icon, that might be less buggy, e.g. the OpenPGP applet one? (We could also wait for the accessibility icon, but since it’s part of GNOME Shell, I guess that it may appear a bit before the ones we stuff in there with topIcons, so to be on the safe side we should IMO wait for an icon managed by topIcons.)
This has the potential to break basically any test, so priority >> normal.
Parent Task: #10288