[Bug] Legend overlaps axis labels

### Version

6.0.0

### Link to Minimal Reproduction

https://echarts.apache.org/examples/en/editor.html?c=line-stack

### Steps to Reproduce

The behaviour can be observed in the example for stacked line chart in the official docs.
Have also observed it in bar charts.

### Current Behavior

Axis labels get obscured by chart legend.

### Expected Behavior

No overlap without additional config

### Environment

```markdown
- OS:
- Browser:
- Framework:
```

### Any additional comments?

Workaround:
```
legend: {
bottom: 0,
padding: [0,0,2,0]
},
```

Open the linked stacked line chart example in the official ECharts documentation and reproduce the overlap; also check a bar chart as reported. Trace the legend and axis-label layout behavior, then verify that the labels remain unobscured without additional configuration and that the documented workaround is no longer needed.

Written by the indexing model from the issue text.