refs and cleanup

Author: SimonCropp

src/Directory.Packages.props

@@ -4,11 +4,11 @@
     <CentralPackageTransitivePinningEnabled>true</CentralPackageTransitivePinningEnabled>
   </PropertyGroup>
   <ItemGroup>
-    <PackageVersion Include="MarkdownSnippets.MsBuild" Version="28.3.0" />
+    <PackageVersion Include="MarkdownSnippets.MsBuild" Version="28.3.1" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.6.0" />
     <PackageVersion Include="Mockly" Version="1.7.1" />
     <PackageVersion Include="NUnit3TestAdapter" Version="6.2.0" />
-    <PackageVersion Include="Polyfill" Version="10.8.1" />
+    <PackageVersion Include="Polyfill" Version="10.9.0" />
     <PackageVersion Include="ProjectDefaults" Version="1.0.174" />
     <PackageVersion Include="Verify" Version="31.19.1" />
     <PackageVersion Include="Verify.NUnit" Version="31.19.1" />