Merge pull request #21175 from apache/fix-type

fix(dataZoom): `handleLabel` should be an optional type

Author: plainheart

src/component/dataZoom/SliderZoomModel.ts

@@ -124,7 +124,7 @@ export interface SliderDataZoomOption extends DataZoomOption, BoxLayoutOptionMix
     brushStyle?: ItemStyleOption
 
     emphasis?: {
-        handleLabel: SliderHandleLabelOption
+        handleLabel?: SliderHandleLabelOption
         handleStyle?: ItemStyleOption
         moveHandleStyle?: ItemStyleOption
     },