pointerA11yTimeout: Adapt to API changes in Mutter

pointerA11yTimeout: Adapt to API changes in Mutter

https://gitlab.gnome.org/GNOME/mutter/-/commit/76166d61 did sneak
in an API change by removing the ClutterInputDevice arguments from
the ClutterSeat::ptr-a11y-timeout-* signals. Through a series of
astonishing coincidences, we don't use those arguments, so just
remove them. Since the rest of the arguments were shifted, this
fixes broken behavior of the PieTimer.

Closes: https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/8654
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/3877>