Bump Nerdbank.GitVersioning from 3.4.216 to 3.4.220 in /Ix.NET/Source

Bumps [Nerdbank.GitVersioning](https://github.com/dotnet/Nerdbank.GitVersioning) from 3.4.216 to 3.4.220.
- [Release notes](https://github.com/dotnet/Nerdbank.GitVersioning/releases)
- [Commits](https://github.com/dotnet/Nerdbank.GitVersioning/compare/v3.4.216...v3.4.220)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Ix.NET/Source/Directory.Build.props

@@ -26,7 +26,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All"/>
-    <PackageReference Include="Nerdbank.GitVersioning" Version="3.4.216" PrivateAssets="all" />
+    <PackageReference Include="Nerdbank.GitVersioning" Version="3.4.220" PrivateAssets="all" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(IsTestProject)' == 'true'">