Delete unused code in DataClassRowMapper

spring-jdbc/src/main/java/org/springframework/jdbc/core/DataClassRowMapper.java

@@ -22,8 +22,6 @@ import java.sql.SQLException;
 
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.TypeConverter;
-import org.springframework.core.DefaultParameterNameDiscoverer;
-import org.springframework.core.ParameterNameDiscoverer;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
@@ -45,8 +43,6 @@ import org.springframework.util.Assert;
  */
 public class DataClassRowMapper<T> extends BeanPropertyRowMapper<T> {
 
-	private static final ParameterNameDiscoverer parameterNameDiscoverer = new DefaultParameterNameDiscoverer();
-
 	@Nullable
 	private Constructor<T> mappedConstructor;