Update kuchikiki and html5ever

[sftse]

The subtree involving kuchikiki and html5ever holds back a number of dependencies from updating. This PR is a small step towards updating that subtree, which contains syn 1.0 and rand 0.7.3.

This updates just kuchikiki and html5ever to the most recent version both are compatible with. The update was not as straightforward as initially assumed. Merging this PR removes the dependency on tauri-utils 1.0, which was leading to cargo dependency resolution errors, and inlines unstable functions from schemars that were relied on and no longer exist.

This depends on a private updated version of wry with which it will compile. The PR to update wry in the same way is here.