[Bug] V4 documentation site still broken

### Version

latest

### Link to Minimal Reproduction

https://echarts.apache.org/v4/zh/option.html

### Steps to Reproduce

- Visit echarts documentation site, go to options doc page [here]
- There is a floating tip linking to the [V4 doc site](https://echarts.apache.org/v4/zh/option.html):
- Click on it, and the V4 doc site is broken:

### Current Behavior

V4 documentation site is completely broken with CSP errors:


### Expected Behavior

Should be able to use V4 documentation site, since it is still linked by latest documentation site.

### Environment

```markdown
Not relevant.
```

### Any additional comments?

According to https://github.com/apache/echarts/issues/20728#issuecomment-2700484590 I'm openning this as new issue rather than just commenting.
Previously I've already commented here: https://github.com/apache/echarts-doc/issues/434#issuecomment-2644732737

The issue with V4 doc site has existed for several months.