Update to Typescript 7

[jeffcharles]

Description of the change

Updates npm/javy to use Typescript 7. Similar to #1248 but this one builds successfully.

Why am I making this change?

#1248 failed and it looks like it needed additional changes to pass.

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.