Bevy 0.17 compatibility patch

I've created a fork of `bevy_vello` compatible with Bevy 0.17: https://github.com/HaHa421/bevy_vello-bevy-0.17 It's used in my migration of `woodpecker_ui`: https://github.com/HaHa421/woodpecker_ui-bevy-0.17 This issue is mainly for visibility and future tracking. Feel free to ping me if you'd like to discuss integration or test compatibility.