Bump Microsoft.NET.Test.Sdk from 18.5.1 to 18.6.0

---
updated-dependencies:
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-version: 18.6.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

src/Directory.Packages.props

@@ -7,7 +7,7 @@
     <PackageVersion Include="BenchmarkDotNet" Version="0.15.0" Pinned="true" />
     <PackageVersion Include="FSharp.Core" Version="11.0.100" />
     <PackageVersion Include="MarkdownSnippets.MsBuild" Version="28.2.0" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.5.1" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.6.0" />
     <PackageVersion Include="Microsoft.Sbom.Targets" Version="4.1.5" />
     <PackageVersion Include="Newtonsoft.Json" Version="13.0.4" />
     <PackageVersion Include="NodaTime" Version="3.3.2" />