🐛[BUG] PageContainer 上面会留白，如何去掉

### 🐛 bug 描述

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### 📷 复现步骤

### 🏞 期望结果

如何去掉这一块空白

### 💻 复现代码

### © 版本信息

@ant-design/pro-components": "^2.6.48"
- umi 版本 4
- 浏览器环境 Google
- 开发环境 windows

### 🚑 其他信息

Start by reproducing the PageContainer snippet with @ant-design/pro-components 2.6.48 and inspect the rendered layout when title and breadcrumbRender are disabled. Confirm which element creates the upper blank space and verify that the result removes it without affecting other PageContainer layouts.

Written by the indexing model from the issue text.