🐛 [BUG]横坐标为不连续number时，柱状图会显示错误

### 🐛 Bug description [Please make everyone to understand it]
横坐标为不连续number时，柱状图会显示错误

> Please provide a link by forking these links [G2Plot](https://codesandbox.io/s/g2plot-issue-template-gzfdq?file=/index.ts) or GitHub repo, a minimal reproduction.
https://codesandbox.io/s/g2plot-issue-template-forked-mv8382?file=/index.ts

* _Required_ **Link to minimal reproduction**:

### 📷 Step to reproduce

### 🏞 Expected result
横坐标为不连续number时，柱状图显示正确

### 🚑 Any additional [like screenshots]

* **G2Plot Version**:任何
* **Platform**:谷歌

Start with the linked CodeSandbox minimal reproduction, opening index.ts and checking the bar chart configuration for a non-contiguous numeric x-axis. Reproduce the incorrect rendering and compare it with the expected result: the bar chart should display correctly for non-contiguous numbers.

Written by the indexing model from the issue text.