refs and cleanup

Author: SimonCropp

src/Directory.Packages.props

@@ -8,10 +8,10 @@
     <PackageVersion Include="Caseless.Fody" Version="1.9.1" />
     <PackageVersion Include="EmptyFiles" Version="8.17.1" />
     <PackageVersion Include="Fody" Version="6.9.3" />
-    <PackageVersion Include="MarkdownSnippets.MsBuild" Version="28.0.0-beta.7" />
+    <PackageVersion Include="MarkdownSnippets.MsBuild" Version="28.0.0-beta.8" />
     <PackageVersion Include="Microsoft.Sbom.Targets" Version="4.1.4" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
-    <PackageVersion Include="Polyfill" Version="9.2.0" />
+    <PackageVersion Include="Polyfill" Version="9.3.0" />
     <PackageVersion Include="ProjectDefaults" Version="1.0.162" />
     <PackageVersion Include="Resourcer.Fody" Version="1.8.1" />
     <PackageVersion Include="System.Collections.Immutable" Version="8.0.0" />