OpenApiClient should allow multiple content-types

[novarx]

Citrus Version
4.2.1

Expected behavior
Given an openapi endpoint
And that endpoint can respond in application/json
And that endpoint can respond in application/xml

When a request with accept: application/xml is executed
And a valid XML is returned

Then the content-type of the response should be valid
And test should pass green

Actual behavior

The test always fails with Values not equal for header element 'Content-Type', expected 'application/json' but was 'application/xml'

Test case sample

@Test
public class OpenApiClientIT extends TestNGCitrusSpringSupport {

    private final int port = SocketUtils.findAvailableTcpPort(8080);

    @BindToRegistry
    private final HttpServer httpServer = new HttpServerBuilder()
            .port(port)
            .timeout(5000L)
            .autoStart(true)
            .defaultStatus(HttpStatus.NO_CONTENT)
            .build();

    @BindToRegistry
    private final HttpClient httpClient = new HttpClientBuilder()
            .requestUrl("http://localhost:%d".formatted(port))
            .build();

    private final OpenApiSpecification petstoreSpec = OpenApiSpecification.from(
            Resources.create("classpath:org/citrusframework/openapi/petstore/petstore-v3.json"));

    @CitrusTest
    public void BUG_should_be_possible_to_switch_content_type__to_xml() {
        variable("petId", "1001");

        when(openapi(petstoreSpec)
                .client(httpClient)
                .send("getPetById")
                .message()
                .accept("application/xml")
                .fork(true));

        then(http().server(httpServer)
                .receive()
                .get("/pet/${petId}")
                .message()
                .accept("@contains('application/xml')@"));

        then(http().server(httpServer)
                .send()
                .response(HttpStatus.OK)
                .message()
                .body("<pet></pet>")
                .contentType("application/xml"));

        then(openapi(petstoreSpec)
                .client(httpClient)
                .receive("getPetById", HttpStatus.OK)
                .message()
                // TODO BUG XML bodies do not seem to work, even if there is just XML as "produces" in the spec
                .body("<pet></pet>")
                // TODO BUG the type/contentType statements are useless, if there is another type in the spec.
                //      even if there are two. i.E:
                // # this will always use JSON as type
                // produces:
                //   - application/json
                //   - application/xml
                .contentType("application/xml")
                .type(XML));
    }
}