[Bug] axisLabel precision causes floating-point error in number formatting (toFixed)

### Version

5.6.0

### Link to Minimal Reproduction

https://echarts.apache.org/examples/en/editor.html?c=bar-simple&lang=ts&code=PYBwLglsB2AEC8sDeAoWsDmAnCATAXMmurADYCmAZmIQMwAM9ANMQL4voAeAgpxAM6FUJWGACeIcoQDkAYwCGYchmBYx0jiVyL5hANrSAsjA2xpAFQCu5U9IDq5XLfMALS7YBiOaQF02msV4BIWJ0cUkZADd5UmsNUNgIaCUsaNJCegA6egA2AHZ6AFY8gCYATgBGHOqavM10AFt5TkJYLIraABYKis7CgA5aIeGu-tgGpMIAWiyS-h68iv68wsY1-bH-EFIIMAA5SwaAI3IsQkL_Yn5TiHJBWD0E4RFYbTBdB4SRLNyizpz-n0xt9smUSv0mLAviQfowynkcoUcpDoegfiVaP0yiiXjDsrkMf1UbAfMDRBIpGYjvIsNIEqxiH5WABuIA

### Steps to Reproduce

see Link to Minimal Reproduction

### Current Behavior

the axis label formatting via (+x).toFixed(precision) in [src/util/number.ts](https://github.com/apache/echarts/blob/master/src/util/number.ts) (line 146) produces floating-point errors.


### Expected Behavior

axis label value should be increased by interval

### Environment

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

### Any additional comments?

_No response_

Start with src/util/number.ts at the referenced line and run the linked minimal reproduction in the ECharts editor. Trace how axisLabel precision reaches toFixed, then verify the reproduction shows labels increasing by the interval without floating-point artifacts.

Written by the indexing model from the issue text.