[SPARK-39606][SQL] Use child stats to estimate order operator

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/statsEstimation/BasicStatsPlanVisitor.scala

@@ -102,9 +102,7 @@ object BasicStatsPlanVisitor extends LogicalPlanVisitor[Statistics] {
 
   override def visitWindow(p: Window): Statistics = fallback(p)
 
-  override def visitSort(p: Sort): Statistics = {
-    BasicStatsPlanVisitor.visit(p.child)
-  }
+  override def visitSort(p: Sort): Statistics = fallback(p)
 
   override def visitTail(p: Tail): Statistics = {
     fallback(p)

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/statsEstimation/SizeInBytesOnlyStatsPlanVisitor.scala

@@ -162,7 +162,7 @@ object SizeInBytesOnlyStatsPlanVisitor extends LogicalPlanVisitor[Statistics] {
 
   override def visitWindow(p: Window): Statistics = visitUnaryNode(p)
 
-  override def visitSort(p: Sort): Statistics = default(p)
+  override def visitSort(p: Sort): Statistics = p.child.stats
 
   override def visitTail(p: Tail): Statistics = {
     val limit = p.limitExpr.eval().asInstanceOf[Int]

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/statsEstimation/BasicStatsEstimationSuite.scala

@@ -360,7 +360,7 @@ class BasicStatsEstimationSuite extends PlanTest with StatsEstimationTestBase {
     checkStats(
       sort,
       expectedStatsCboOn = expectedSortStats,
-      expectedStatsCboOff = Statistics(sizeInBytes = expectedSize))
+      expectedStatsCboOff = expectedSortStats)
   }
 
   /** Check estimated stats when cbo is turned on/off. */