type: update unknown with SliderRef (#43094)

components/slider/SliderTooltip.tsx

@@ -1,3 +1,4 @@
+import type { SliderRef } from 'rc-slider/lib/Slider';
 import raf from 'rc-util/lib/raf';
 import { composeRef } from 'rc-util/lib/ref';
 import * as React from 'react';
@@ -5,7 +6,7 @@ import { useRef } from 'react';
 import type { TooltipProps } from '../tooltip';
 import Tooltip from '../tooltip';
 
-const SliderTooltip = React.forwardRef<unknown, TooltipProps>((props, ref) => {
+const SliderTooltip = React.forwardRef<SliderRef, TooltipProps>((props, ref) => {
   const { open } = props;
   const innerRef = useRef<any>(null);
 
@@ -36,4 +37,8 @@ const SliderTooltip = React.forwardRef<unknown, TooltipProps>((props, ref) => {
   return <Tooltip ref={composeRef(innerRef, ref)} {...props} />;
 });
 
+if (process.env.NODE_ENV !== 'production') {
+  SliderTooltip.displayName = 'SliderTooltip';
+}
+
 export default SliderTooltip;