Remov redundant import of dart:math (#65060)

packages/flutter/lib/src/material/slider.dart

@@ -6,7 +6,6 @@
 
 import 'dart:async';
 import 'dart:math' as math;
-import 'dart:math';
 
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/foundation.dart';
@@ -1341,10 +1340,10 @@ class _RenderSlider extends RenderBox with RelayoutWhenSystemFontsChangeMixin {
   double computeMaxIntrinsicWidth(double height) => _minPreferredTrackWidth + _maxSliderPartWidth;
 
   @override
-  double computeMinIntrinsicHeight(double width) => max(_minPreferredTrackHeight, _maxSliderPartHeight);
+  double computeMinIntrinsicHeight(double width) => math.max(_minPreferredTrackHeight, _maxSliderPartHeight);
 
   @override
-  double computeMaxIntrinsicHeight(double width) => max(_minPreferredTrackHeight, _maxSliderPartHeight);
+  double computeMaxIntrinsicHeight(double width) => math.max(_minPreferredTrackHeight, _maxSliderPartHeight);
 
   @override
   bool get sizedByParent => true;
@@ -1353,7 +1352,7 @@ class _RenderSlider extends RenderBox with RelayoutWhenSystemFontsChangeMixin {
   void performResize() {
     size = Size(
       constraints.hasBoundedWidth ? constraints.maxWidth : _minPreferredTrackWidth + _maxSliderPartWidth,
-      constraints.hasBoundedHeight ? constraints.maxHeight : max(_minPreferredTrackHeight, _maxSliderPartHeight),
+      constraints.hasBoundedHeight ? constraints.maxHeight : math.max(_minPreferredTrackHeight, _maxSliderPartHeight),
     );
   }