This reverts commit 47d8bdd1c3.
There are runtime reasons why creating a tray can fail, so the correct approach is not to assume that just because a platform supports a tray that trays are available. Instead, you should create a tray at application startup, for the lifetime of the application, and handle failures at that point.
Closes https://github.com/libsdl-org/SDL/pull/13632
SDL_HINT_QUIT_ON_LAST_WINDOW_CLOSE will not fire if there are active tray icons. This impacts only applications that create tray icons, and that at least one icon outlives the last visible top-level window. SDL_EVENT_QUIT will fire when the last active tray is destroyed if there are no active windows.