update polyfill to 10.1.1

Author: alastairlundy

Directory.Packages.props

@@ -4,7 +4,7 @@
   </PropertyGroup>
   <ItemGroup>
     <PackageVersion Include="Microsoft.Bcl.Memory" Version="10.0.5" />
-    <PackageVersion Include="Polyfill" Version="9.23.0" PrivateAssets="all" />
+    <PackageVersion Include="Polyfill" Version="10.1.1" PrivateAssets="all" />
     <PackageVersion Include="Meziantou.Analyzer" Version="3.0.43">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>