refactor(mybatis): 替换getLast()方法调用

- 使用get(elements.size() - 1)替代getLast()方法
- 确保代码在不同Java版本中的兼容性
- 避免潜在的NoSuchElementException异常

Author: pfangit

src/main/java/io/github/xbeeant/mybatis/extend/plugins/XstudioMapperPlugin.java

@@ -1029,7 +1029,7 @@ private void replaceKeyParam(XmlElement element, IntrospectedTable introspectedT
         if (primaryKeyColumns.size() == 1) {
             List<VisitableElement> elements = element.getElements();
             // get where text element
-            VisitableElement visitableElement = elements.getLast();
+            VisitableElement visitableElement = elements.get(elements.size() - 1);
             String whereContent = ((TextElement) visitableElement).getContent();
             int start = whereContent.indexOf("#{");
             int end = whereContent.indexOf(",");
@@ -1045,7 +1045,7 @@ private void replaceKeyParam(XmlElement element, IntrospectedTable introspectedT
 
     private void replaceWithWhereExampleElement(XmlElement element) {
         List<VisitableElement> elements = element.getElements();
-        VisitableElement visitableElement = elements.getLast();
+        VisitableElement visitableElement = elements.get(elements.size() - 1);
         // remove
         // <if test="_parameter != null">
         //      <include refid="Example_Where_Clause" />