fix(leagueTournament): 恢复比赛项目选择功能

- 移除了比赛项目表单项的注释包裹
- 重新启用游戏变体类型下拉选择功能
- 保留了原有的选项数据绑定逻辑

src/views/system/physical/leagueTournament/index.vue

@@ -163,11 +163,11 @@
         <el-form-item label="赛事标题" prop="title">
           <el-input v-model="form.title" placeholder="请输入赛事标题" />
         </el-form-item>
-<!--        <el-form-item label="比赛项目" prop="gameVariant">
+        <el-form-item label="比赛项目" prop="gameVariant">
           <el-select aria-required="true" v-model="form.gameVariant" placeholder="请选择">
             <el-option v-for="dict in game_variant_type" :key="dict.value" :label="dict.label" :value="dict.value"> </el-option>
           </el-select>
-        </el-form-item>-->
+        </el-form-item>
         <el-form-item label="上传图片" prop="imageUrl">
           <div class="upload-container">
             <el-upload