Merge pull request #1680 from dotnet/dependabot/nuget/Rx.NET/Source/Nerdbank.GitVersioning-3.4.255

Author: clairernovotny

Rx.NET/Source/Directory.build.props

@@ -28,7 +28,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All"/>
-    <PackageReference Include="Nerdbank.GitVersioning" Version="3.4.244" PrivateAssets="all" />
+    <PackageReference Include="Nerdbank.GitVersioning" Version="3.4.255" PrivateAssets="all" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(IsTestProject)' == 'true'">