refactor: remove usage of deprecated request.routeConfig

[inyourtime]

request.routeConfig was removed in Fastify v5
ref. https://fastify.dev/docs/latest/Guides/Migration-Guide-V5/#streamlined-access-to-route-definition

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

[inyourtime]

In Helmet v8.1.0 (see PR), errors are now thrown directly instead of being passed to a callback.
This makes any error handling logic in the callback unreachable.
not sure is this ok?
or simply:

function done () {}