[Bug] If selected series has null value, the tooltip doesn't show with showTip dispatchAction

### Version

5.6.0

### Link to Minimal Reproduction

https://codepen.io/petercsaki/pen/jEOWgre?editors=0010

### Steps to Reproduce

1. Create a chart with multiple series, where one has `null` values. Enable tooltips for it.
2. Trigger the tooltip with `dispatchAction` `showTip`, with the `seriesIndex` pointing to the series that has `null` value.

### Current Behavior

The tooltip doesn't show at all.

### Expected Behavior

The tooltip should show.

### Environment

```markdown
- OS: any
- Browser: any
- Framework: none
```

### Any additional comments?

When the selected series has a non null value, the tooltip shows, even if other series have nulls.
The same problem was fixed in 5.3 for the normal, hover over tooltips. https://github.com/apache/echarts/issues/15757 The event driven tooltip was not fixed back then.