Revert "D-Bus system tray: properly check whether StatusNotifierHost available"

Revert "D-Bus system tray: properly check whether StatusNotifierHost available"

Origin: upstream, https://code.qt.io/cgit/qt/qtbase.git/commit/?id=447f3ade9a284d52
Last-Update: 2024-07-24

The original commit was made based on a KDE workaround for
libdbusmenu-qt crash, but Qt is not using libdbusmenu-qt, Qt is not
watching for StatusNotifierHost registration and Qt is not capable
to switch backends on the fly leading to tray support being
not detected on Plasma Wayland sessions and falling back to the poor
legacy protocol on X11.

Gbp-Pq: Name revert_statusnotifierhost_checking.diff