Refactor(coding actions): Apply @StrutsParameter and update web.xml schema

- Apply required `@StrutsParameter` to action setters for Struts 7.0+ compatibility.
- Update web.xml to Jakarta EE 10 namespace and Servlet 6.0 schema.

Author: fp024

coding-actions/src/main/java/org/apache/struts/helloworld/action/HelloWorldAction.java

@@ -2,6 +2,7 @@
 
 import org.apache.struts.helloworld.model.MessageStore;
 import org.apache.struts2.ActionSupport;
+import org.apache.struts2.interceptor.parameter.StrutsParameter;
 
 /**
  * Acts as a Struts 2 controller that responds
@@ -33,6 +34,7 @@ public String getUserName() {
         return userName;
     }
 
+    @StrutsParameter
     public void setUserName(String userName) {
         this.userName = userName;
     }

coding-actions/src/main/webapp/WEB-INF/web.xml

@@ -1,5 +1,8 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<web-app id="WebApp_ID" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
+<web-app id="WebApp_ID" version="6.0"
+    xmlns="https://jakarta.ee/xml/ns/jakartaee"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee https://jakarta.ee/xml/ns/jakartaee/web-app_6_0.xsd">
 <display-name>Coding Actions</display-name>
     <welcome-file-list>
         <welcome-file>index.jsp</welcome-file>