Update dependency Microsoft.NET.Test.Sdk to v18 (#5126)

Co-authored-by: dependencyupdates[bot] <218638057+dependencyupdates[bot]@users.noreply.github.com>

Author: dependencyupdates[bot]

src/Directory.Packages.props

@@ -28,7 +28,7 @@
     <PackageVersion Include="Microsoft.Extensions.Logging.Configuration" Version="8.0.1" />
     <PackageVersion Include="Microsoft.Extensions.Logging.Abstractions" Version="8.0.3" />
     <PackageVersion Include="Microsoft.Extensions.TimeProvider.Testing" Version="8.10.0" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.0" />
     <PackageVersion Include="Microsoft-WindowsAPICodePack-Shell" Version="1.1.5" />
     <PackageVersion Include="Mindscape.Raygun4Net.NetCore" Version="11.2.1" />
     <PackageVersion Include="NLog.Extensions.Logging" Version="5.4.0" />