ical native build failure

[JiriOndrusek]

Description

Upgrade of ical4j in camel (see commit) is causing an error during native execution:

UnresolvedElementException: Discovered unresolved method during parsing: net.fortuna.ical4j.validate.schema.JsonSchemaValidator.<init>(java.net.URL). This error is reported at image build time because class net.fortuna.ical4j.validate.schema.SchemaValidatorFactory is registered for linking at image build time by command line

It is unclear to me, why the error is happening, because the Quarkus knows this class.

I noticed, that this method is not visited during Camel or Camel Quarkus tests execution. Therefore it might be possible, that the method is not needed for the Camel/camel quarkus, I fixed the problem temporarily by the workaround (substitution of the method). It would be nice to investigate the problem more and if it is possible to trigger this validation from Camel/Camel Quarkus -> the case should be covered by the tests.

[jamesnetherton]

It likely happens because com.github.erosb:everit-json-schema is declared as runtime scope and optional.

We could make the method substitution conditional based on the presence of some class in everit-json-schema.

Example of how I did something similar for another extension here #4926.