Update to Wasmtime 42

[jeffcharles]

Description of the change

Updates to Wasmtime 42.

• Removed configuration for to set async to true since it's no longer necessary
• Added some wrappers to convert wasmtime::Error to anyhow::Error
• Updated a function we are using to inspect the store when there's a caller error to work on wasmtime errors instead of anyhow ones

Why am I making this change?

Besides keeping a dependency up-to-date, this should close an open security issue.

Checklist

• I've updated the default plugin import namespace and incremented the major version of javy-plugin-api if the QuickJS bytecode has changed.
• [xj] I've updated the relevant CHANGELOG files if necessary. Changes to javy-cli, javy-plugin, and javy-plugin-processing do not require updating CHANGELOG files.
• I've updated the relevant crate versions if necessary. Versioning policy for library crates
• I've updated documentation including crate documentation if necessary.