RFC: support for svelte 5

[laciferin2024]

Svelte 5 is quite stable now, it would be great to roll out support for svelte 5.

[benmccann]

This would require changes in Svelte 5 itself.

In Svelte 4, Svelte Native was implemented by overriding the DOM creation methods. However, Svelte 5 doesn't use those same methods anymore and so that won't work. The foreign namespace solution needs to be replaced with a custom render inside Svelte 5. That won't happen in time for Svelte 5.0, but is something that should be able to be added in a later minor release in a non-breaking fashion

[NathanWalker]

Anything we can do to help here @halfnelson @benmccann ?

[victorriba]

I think this project lacks maintainers?

[benmccann]

I've opened an issue to track custom renderer support in Svelte: sveltejs/svelte#15470