[Bug] emphasis.handleLabel is now a required field

[Bilge]

Version

6.0.0

Link to Minimal Reproduction

https://github.com/apache/echarts/pull/20082/files#r2252240360

Steps to Reproduce

Please see https://github.com/apache/echarts/pull/20082/files#r2252240360

Current Behavior

TS2741: Property handleLabel is missing in type { handleStyle: { borderColor: string; }; } but required in type

Expected Behavior

No TS error.

Environment

- OS: Windows
- Browser: Firefox 141
- Framework: n/a

Any additional comments?

This is a BC break between 5.5 -> 6.0.