Update BenchmarkDotNet to 0.15.8

Author: JimBobSquarePants

tests/Directory.Build.targets

@@ -18,7 +18,7 @@
 
   <ItemGroup>
     <!-- Test Dependencies -->
-    <PackageReference Update="BenchmarkDotNet" Version="0.13.1" />
+    <PackageReference Update="BenchmarkDotNet" Version="0.15.8" />
     <PackageReference Update="Microsoft.DotNet.RemoteExecutor" Version="8.0.0-beta.23580.1" />
     <PackageReference Update="Microsoft.DotNet.XUnitExtensions" Version="8.0.0-beta.23580.1" />
     <PackageReference Update="Moq" Version="4.20.72" />