refs and cleanup

Author: SimonCropp

src/Directory.Packages.props

@@ -7,7 +7,7 @@
     <PackageVersion Include="MarkdownSnippets.MsBuild" Version="28.0.0-beta.25" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
     <PackageVersion Include="Newtonsoft.Json" Version="13.0.4" />
-    <PackageVersion Include="Polyfill" Version="9.7.7" />
+    <PackageVersion Include="Polyfill" Version="9.8.0" />
     <PackageVersion Include="ProjectDefaults" Version="1.0.170" />
     <PackageVersion Include="Verify" Version="31.10.0" />
     <PackageVersion Include="Verify.DiffPlex" Version="3.1.2" />