Convert velato to use anyrender instead than vello

[nicoburns]

Motivation

Allows velato to be used with Vello CPU, Vello Hybrid, and Skia in addition to Vello. It also allow people to "bring their own renderer" if they have a custom rendering setup they want to support.

• Fixes Use velato independently of vello #74

Changes made

• Depend on and import kurbo and peniko directly rather than through vello
• Remove vello dependency. Add anyrender dependency.
• In render.rs: replace vello::Scene with impl anyrender::PaintScene
• In examples/scenes/src/lottie.rs: use anyrender_vello::VelloScenePainter to bridge between vello::Scene and anyrender::PaintScene

[nuzzles]

I personally like this change but one snag I don't really love is that it seems like anyrender_vello needs to be updated prior to velato? No longer just Vello, we would have a new obstacle in the middle.

Unless I'm misunderstanding.

[nuzzles]

Needs change log update

[nicoburns]

I personally like this change but one snag I don't really love is that it seems like anyrender_vello needs to be updated prior to velato? No longer just Vello, we would have a new obstacle in the middle.

Correct, but that should be quick. I have an AnyRender update for Vello 0.7 ready to go once the Sparse Strips variants of Vello drop (should be tomorrow). The upside is that if the version of vello uses the same peniko version as the previous version of vello then velato wouldn't need to updated at all (we'd put out a new version of anyrender_vello that depends on the same version of anyrender, and as velato would only depend on anyrender it would work with the new anyrender_vello automatically)

[waywardmonkeys]

I think this might need a broader discussion. Please wait before landing.

[waywardmonkeys]

Want a broader discussion.

[nuzzles]

Want a broader discussion.

There was some prior discussion in #74 (comment)

[nicoburns]

Closing in favour of #95