聚合热力图在拖动图例范围的时候，x、y轴的缩略轴会出现undefined

### 问题描述

当我拖动热力的范围图例，如果这个范围没有数据，则x、y轴都会变成undefined

### 重现链接

https://g2.antv.antgroup.com/zh/examples/general/cell/#cell-aggregated

### 重现步骤

代码
/**
* A recreation of this demo: https://vega.github.io/vega-lite/examples/rect_heatmap_weather.html
*/
import { Chart } from '@antv/g2';

const chart = new Chart({
container: 'container',
height: 300,
});

const data = [
{
"date": "2012-01-01T00:00:00.000Z",
"precipitation": 0,
"temp_max": 200,
"temp_min": 5,
"wind": 4.7,
"weather": "drizzle"
},
{
"date": "2012-01-02T00:00:00.000Z",
"precipitation": 10.9,
"temp_max": 10,
"temp_min": 2.8,
"wind": 4.5,
"weather": "rain"
},
{
"date": "2012-01-03T00:00:00.000Z",
"precipitation": 0.8,
"temp_max": 2,
"temp_min": 7.2,
"wind": 2.3,
"weather": "rain"
},
{
"date": "2012-01-05T00:00:00.000Z",
"precipitation": 1.3,
"temp_max": 8.9,
"temp_min": 2.8,
"wind": 6.1,
"weather": "rain"
},
{
"date": "2012-01-06T00:00:00.000Z",
"precipitation": 2.5,
"temp_max": 4.4,
"temp_min": 2.2,
"wind": 2.2,
"weather": "rain"
},
{
"date": "2012-01-07T00:00:00.000Z",
"precipitation": 0,
"temp_max": 7.2,
"temp_min": 2.8,
"wind": 2.3,
"weather": "rain"
},
{
"date": "2012-01-08T00:00:00.000Z",
"precipitation": 0,
"temp_max": 10,
"temp_min": 2.8,
"wind": 2,
"weather": "sun"
},
]

chart
.cell()
.data(data)
// .transform({ type: 'group', color: 'max' })
.encode('x', 'date')
.encode('y', 'weather')
.encode('color', 'temp_max')
.slider('x')
.slider('y')
.style('inset', 0.5)
.scale('color', { palette: 'gnBu' })
.animate('enter', { type: 'fadeIn' });

chart.render();

### 预期行为

预期不应该是undefined，可以为空或者 0

### 平台

- 操作系统: [macOS, Windows, Linux, React Native ...]
- 网页浏览器: [Google Chrome, Safari, Firefox]

### 屏幕截图或视频（可选）

### 补充说明（可选）

_No response_

Start by running the linked aggregated cell example with the provided TypeScript reproduction, then drag the heatmap range until it contains no data. Trace the x- and y-axis thumbnail updates during that interaction; done means empty ranges no longer render as undefined, using an empty value or 0 instead.

Written by the indexing model from the issue text.