Add microprofile-oneof-interface sample to java client jdk11 workflow

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: Ignacio-Vidal

.github/workflows/samples-java-client-jdk11.yaml

@@ -87,6 +87,7 @@ jobs:
           - samples/client/petstore/java/microprofile-rest-client-3.0-jackson-with-xml
           - samples/client/petstore/java/microprofile-rest-client-3.0-mutiny
           - samples/client/petstore/java/microprofile-rest-client-with-useSingleRequestParameter
+          - samples/client/petstore/java/microprofile-oneof-interface
           - samples/client/petstore/java/apache-httpclient
           - samples/client/petstore/java/feign
           - samples/client/petstore/java/feign-hc5