Update wlroots to 0.17.2

[sdilts]

wlroots Release notes: https://gitlab.freedesktop.org/wlroots/wlroots/-/releases/0.17.0

The following things were affected/added:

• The output mode change event was removed in favor of the general output commit event. Remove the mode handler code instead of adapting to the changes, as there may be better ways to handle it. (https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/3911).
• Use the wlr_scene_output_layout helper, which sets various things up that were implicilty done before. https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/4318
• Since the backend no longer changes the ouput mode behind our code's back, we handle listen to the request_state event to have the previous behavior. https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/2693
• Use the wlr_output_state event to atomically update the output state upon initialization.
• Change where the xdg map events are stored: https://gitlab.freedesktop.org/wlroots/wlroots/-/merge_requests/4043