refs and cleanup

Author: SimonCropp

src/Directory.Packages.props

@@ -11,7 +11,7 @@
     <PackageVersion Include="NUnit" Version="4.4.0" />
     <PackageVersion Include="NUnit3TestAdapter" Version="6.1.0" />
     <PackageVersion Include="ProjectDefaults" Version="1.0.170" />
-    <PackageVersion Include="Polyfill" Version="9.7.7" />
+    <PackageVersion Include="Polyfill" Version="9.8.0" />
     <PackageVersion Include="Verify.DiffPlex" Version="3.1.2" />
     <PackageVersion Include="Verify.NUnit" Version="31.10.0" />
   </ItemGroup>