When motionabsolute() is called from warpd, event->time_msec is 0, so motionnotify() doesn't call wlr_cursor_move(). Fix this by explicitly warping the cursor in this case, like it was done before implementing pointer constraints.

I don't know if this is a bug in warpd or time_msec is always 0 with virtual pointers, since the only other software that uses the virtual pointer protocol I know of is wl-kbptr, and I can't get that to work with dwl at all.