docs(benchmark): Improve documentation clarity for BenchmarkResult class

Updated the comment for the BenchmarkResult class to enhance clarity by rephrasing it from "Represents the final aggregated result of a benchmark" to "The final aggregated result of a benchmark." This change aims to improve the readability of the code documentation.

Author: abbashosseinii

pkgs/collection/benchmark/sort_comparison_benchmark.dart

@@ -60,7 +60,7 @@ class DatasetGenerator {
   }
 }
 
-/// Represents the final aggregated result of a benchmark.
+/// The final aggregated result of a benchmark.
 class BenchmarkResult {
   final double mean;
   final int median;