chore(header): 注释掉2025年贡献者大会选项

- 在下拉菜单中临时注释掉2025年的选项
- 保留2024年及往年的选项不变
- 为后续重新启用做准备

src/components/PortalHeader.vue

@@ -106,7 +106,8 @@
                 >贡献者大会</span
               >
               <el-dropdown-menu slot="dropdown">
-                <el-dropdown-item command="three">2024</el-dropdown-item>
+<!--                <el-dropdown-item command="four">2025</el-dropdown-item>-->
+                <el-dropdown-item command="three" divided>2024</el-dropdown-item>
                 <el-dropdown-item command="one" divided>2023</el-dropdown-item>
                 <el-dropdown-item command="two" divided>2022</el-dropdown-item>
               </el-dropdown-menu>
@@ -422,6 +423,7 @@ export default {
         one: urlPre + "/web/contributornew/index",
         two: urlPre + "/web/contributor/index",
         three: urlPre + "/web/contributor_2024/index",
+        four: urlPre + "/web/contributor_2025/index",
       };
       window.open(obj[val]);
     },