Upgrade jsonld dependency to 9.0.0

This upgrade eliminates the rdf-canonize-native runtime dependency that
was causing build issues in bundler environments like Next.js, Nuxt, and
other webpack-based tools.

The rdf-canonize-native package is no longer maintained, and its
speculative require() was causing module resolution errors during builds.
Version 9.0.0 of jsonld uses rdf-canonize 5.0.0, which has completely
dropped native binding support in favor of the performant pure JavaScript
implementation.

This resolves compatibility issues when using Fedify in web frameworks,
particularly Nuxt projects where the native dependency was problematic.

Fixes: https://github.com/digitalbazaar/jsonld.js/issues/567
Related: https://github.com/digitalbazaar/rdf-canonize/pull/84