refs and cleanup

Author: SimonCropp

src/Directory.Packages.props

@@ -5,11 +5,11 @@
   </PropertyGroup>
   <ItemGroup>
     <PackageVersion Include="MarkdownSnippets.MsBuild" Version="28.0.0" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.3.0" />
     <PackageVersion Include="OpenTelemetry" Version="1.15.0" />
     <PackageVersion Include="OpenTelemetry.Exporter.InMemory" Version="1.15.0" />
     <PackageVersion Include="Microsoft.Extensions.Logging" Version="10.0.3" />
-    <PackageVersion Include="Polyfill" Version="9.11.0" />
+    <PackageVersion Include="Polyfill" Version="9.13.0" />
     <PackageVersion Include="Verify" Version="31.13.2" />
     <PackageVersion Include="Verify.DiffPlex" Version="3.1.2" />
     <PackageVersion Include="Verify.XunitV3" Version="31.13.2" />