ClassNotFoundException thrown when processing enums with annotations

https://github.com/smallrye/smallrye-open-api/issues/1508

We can workaround the issue by calling OpenApiProcessor.modelFromAnnotations(...) with a ClassLoader that delegates to both the io.smallrye.openapi and deployment module.

However, ideally upstream should either allow the ClassLoader used to load AnnotationScanner instances to be specified independently from the ClassLoader used to load application enum classes; or allow WildFly to bypass the service loading required to create its AnnotationScanner instances.