SqlStreamInput/Output use TransportVersion from a read-in Version constant. We need to remove the useage of `transportVersion` field
x-pack/plugin/sql/qa/mixed-node/src/javaRestTest/java/org/elasticsearch/xpack/sql/qa/mixed_node/SqlSearchIT.java
import org.elasticsearch.xcontent.json.JsonXContent;
import org.elasticsearch.xpack.ql.TestNode;
import org.elasticsearch.xpack.ql.TestNodes;
import org.junit.After;
import org.junit.Before;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.function.BiConsumer;
import java.util.function.Consumer;
import java.util.stream.Collectors;
import static java.util.Collections.unmodifiableMap;
import static org.elasticsearch.xpack.ql.TestUtils.buildNodeAndVersions;
import static org.elasticsearch.xpack.ql.TestUtils.readResource;
public class SqlSearchIT extends ESRestTestCase {
    private static final Version VERSION_FIELD_QL_INTRODUCTION = Version.V_8_4_0;
    private static final String index = "test_sql_mixed_versions";
    private static int numShards;
    private static int numReplicas = 1;
    private static int numDocs;
    private static TestNodes nodes;
    private static List<TestNode> newNodes;
    private static List<TestNode> bwcNodes;
    private static Version bwcVersion;
    @Before
    public void createIndex() throws IOException {