chore(deps): update dependency microsoft.net.test.sdk to 18.6.0 (#166)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

tests/Atypical.VirtualFileSystem.GitHub.Tests/Atypical.VirtualFileSystem.GitHub.Tests.csproj

@@ -7,7 +7,7 @@
 
     <ItemGroup>
         <PackageReference Include="Shouldly" Version="4.3.0" />
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.5.1" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.6.0" />
         <PackageReference Include="NSubstitute" Version="5.3.0" />
         <PackageReference Include="xunit" Version="2.9.3" />
         <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">

tests/Atypical.VirtualFileSystem.UnitTests/Atypical.VirtualFileSystem.UnitTests.csproj

@@ -7,7 +7,7 @@
 
     <ItemGroup>
         <PackageReference Include="Shouldly" Version="4.3.0" />
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.5.1" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.6.0" />
         <PackageReference Include="xunit" Version="2.9.3" />
         <PackageReference Include="xunit.runner.visualstudio" Version="3.1.5">
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>