refs and cleanup

Author: SimonCropp

src/Directory.Packages.props

@@ -21,7 +21,7 @@
     <PackageVersion Include="MSTest" Version="3.6.3" />
     <PackageVersion Include="MSTest.TestFramework" Version="3.6.3" />
     <PackageVersion Include="NUnit3TestAdapter" Version="4.6.0" />
-    <PackageVersion Include="Polyfill" Version="7.4.1" />
+    <PackageVersion Include="Polyfill" Version="7.5.0" />
     <PackageVersion Include="ProjectDefaults" Version="1.0.144" />
     <PackageVersion Include="PublicApiGenerator" Version="11.1.0" />
     <PackageVersion Include="SimpleInfoName" Version="3.1.0" />