Slider: Fix style problem when clicking slider bar(#15561)

packages/slider/src/button.vue

@@ -226,6 +226,7 @@
         value = parseFloat(value.toFixed(this.precision));
         this.$emit('input', value);
         this.$nextTick(() => {
+          this.displayTooltip();
           this.$refs.tooltip && this.$refs.tooltip.updatePopper();
         });
         if (!this.dragging && this.value !== this.oldValue) {