Remove cargo vet

[jeffcharles]

Description of the change

Removes cargo-vet

Why am I making this change?

See #1144 (comment). cargo-vet adds toil to any dependency change and we're not getting the benefits we were hoping out of it.

Checklist

• I've updated the default plugin import namespace and incremented the major version of javy-plugin-api if the QuickJS bytecode has changed.
• 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.