Upstream issue: https://github.com/quarkiverse/quarkus-langchain4j/issues/1863
QUARKUS-Issue: https://issues.redhat.com/browse/QUARKUS-6774 

Steps to reproduce:
1. `git clone -b 1.2 git@github.com:quarkiverse/quarkus-langchain4j.git`
2. `mvn clean verify -V -B --no-transfer-progress -fae -Dquarkus.langchain4j.openai.api-key=$API_KEY -Dquarkus.platform.version=3.27.0.redhat-00002 -Dquarkus.platform.artifact-id=quarkus-bom -Dquarkus.platform.group-id=com.redhat.quarkus.platform -Dplatform-deps -DskipTests=false -DskipITs=false -Dmaven.repo.local=$REPO -Dnative -Dquarkus.native.container-build=true -Dquarkus.native.container-runtime=docker -Dquarkus.native.builder-image=registry.access.redhat.com/quarkus/mandrel-for-jdk-21-rhel8:23.1 -Dquarkus.native.native-image-xmx=4g -pl chatbot`

Not needed workaround since already fixed (but for gageing what was wrong):

As explained here https://quarkus.io/guides/writing-native-applications-tips#registerForReflection I believe that a possible workaround would be explicitly register that class for reflection (even though I probably wouldn't suggest to do this), something like: 

@RegisterForReflection(targets={ dev.langchain4j.model.openai.internal.embedding.OpenAiEmbeddingDeserializer.class })
public class MyReflectionConfiguration {
}

SME: Mario Fusco
QE: Fedor Dudinsky