Merge pull request #1148 from dotnet/dependabot/nuget/Rx.NET/Source/Nerdbank.GitVersioning-3.1.68

Author: dependabot-preview[bot]

Rx.NET/Source/Directory.build.props

@@ -25,7 +25,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All"/>
-    <PackageReference Include="Nerdbank.GitVersioning" Version="3.0.50" PrivateAssets="all" />
+    <PackageReference Include="Nerdbank.GitVersioning" Version="3.1.68" PrivateAssets="all" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(IsTestProject)' == 'true'">