refs and cleanup

Author: SimonCropp

src/Directory.Packages.props

@@ -7,12 +7,12 @@
     <PackageVersion Include="ClosedXML" Version="0.105.0" />
     <PackageVersion Include="DeterministicIoPackaging" Version="0.13.0" />
     <PackageVersion Include="DocumentFormat.OpenXml" Version="3.3.0" />
-    <PackageVersion Include="MarkdownSnippets.MsBuild" Version="28.0.0-beta.7" />
+    <PackageVersion Include="MarkdownSnippets.MsBuild" Version="28.0.0-beta.8" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
     <PackageVersion Include="Microsoft.Office.Interop.Excel" Version="16.0.18925.20022" />
     <PackageVersion Include="NUnit" Version="4.4.0" />
     <PackageVersion Include="NUnit3TestAdapter" Version="5.2.0" />
-    <PackageVersion Include="Polyfill" Version="9.2.0" />
+    <PackageVersion Include="Polyfill" Version="9.3.0" />
     <PackageVersion Include="ProjectDefaults" Version="1.0.162" />
     <PackageVersion Include="Verify" Version="31.7.2" />
     <PackageVersion Include="Verify.DiffPlex" Version="3.1.2" />