Bump Microsoft.NET.Test.Sdk from 18.4.0 to 18.5.1 (#350)

---
updated-dependencies:
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-version: 18.5.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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Author: dependabot[bot]

Directory.Packages.props

@@ -11,7 +11,7 @@
     <PackageVersion Include="Microsoft.CodeAnalysis.Analyzers" Version="5.3.0" PrivateAssets="all" />
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="5.3.0" PrivateAssets="all" />
     <PackageVersion Include="Microsoft.CodeAnalysis.Common" Version="5.3.0" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.4.0" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.5.1" />
     <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="10.0.203" PrivateAssets="All" />
     <PackageVersion Include="Microsoft.VisualStudio.Interop" Version="17.14.40260" />
     <PackageVersion Include="Microsoft.Windows.CsWin32" Version="0.3.275" />