test: use annotation to simplify register servlet

vul/vul-webapp-expression/src/main/java/JinJavaServlet.java

@@ -2,6 +2,7 @@ import com.google.common.collect.Maps;
 import com.hubspot.jinjava.Jinjava;
 
 import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
 import javax.servlet.http.HttpServlet;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
@@ -12,6 +13,7 @@ import java.util.Map;
  * @author ReaJason
  * @since 2025/1/30
  */
+@WebServlet("/jinjava")
 public class JinJavaServlet extends HttpServlet {
     @Override
     protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {