Bump Microsoft.NET.Test.Sdk from 18.7.0 to 18.8.1

---
updated-dependencies:
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-version: 18.8.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

Directory.Packages.props

@@ -22,7 +22,7 @@
     <PackageVersion Include="Microsoft.Extensions.Logging" Version="10.0.7" />
     <PackageVersion Include="Microsoft.Extensions.DependencyInjection" Version="10.0.7" />
     <PackageVersion Include="Microsoft.VisualStudio.Azure.Containers.Tools.Targets" Version="1.23.0" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.7.0" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.8.1" />
     <PackageVersion Include="Spectre.Console" Version="0.57.2" />
     <PackageVersion Include="TestableIO.System.IO.Abstractions.TestingHelpers" Version="22.1.1" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.5" />