rootston: Disable keyboard focus on inactive views

After clicking on something non-interactive, the current view was getting deactivated, but still received keyboard events. roots_seat_set_focus now changes both together in this case.

rootston/seat.c

@@ -798,6 +798,7 @@ void roots_seat_set_focus(struct roots_seat *seat, struct roots_view *view) {
 
 	if (view == NULL) {
 		seat->cursor->mode = ROOTS_CURSOR_PASSTHROUGH;
+		wlr_seat_keyboard_clear_focus(seat->seat);
 		return;
 	}