chore(deps): update dependency microsoft.net.test.sdk to v18

Author: renovate[bot]

src/Directory.Packages.props

@@ -30,7 +30,7 @@
     <PackageVersion Include="Avalonia.Desktop" Version="11.3.7" />
     <PackageVersion Include="Microsoft.Extensions.Logging.Debug" Version="9.0.0" />
     <PackageVersion Include="ReactiveUI.Maui" Version="22.0.1" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.0" />
     <PackageVersion Include="System.Formats.Asn1" Version="9.0.0" />
     <PackageVersion Include="xunit" Version="2.9.3" />
     <PackageVersion Include="xunit.runner.console" Version="2.9.3" />