use nuget pack task from the package instead of the sdk (#46438)

* use nuget pack task from the package instead of the sdk

* Update Directory.Build.targets

* Update Versions.props

* Update Versions.props

* Update Directory.Build.targets
Co-authored-by: NViktor Hofer <viktor.hofer@microsoft.com>

eng/Versions.props

@@ -59,6 +59,8 @@
     <MicrosoftDotNetBuildTasksInstallersVersion>6.0.0-beta.20621.12</MicrosoftDotNetBuildTasksInstallersVersion>
     <MicrosoftDotNetRemoteExecutorVersion>6.0.0-beta.20621.12</MicrosoftDotNetRemoteExecutorVersion>
     <MicrosoftDotNetVersionToolsTasksVersion>6.0.0-beta.20621.12</MicrosoftDotNetVersionToolsTasksVersion>
+    <!-- NuGet dependencies -->
+    <NuGetBuildTasksPackVersion>5.9.0-preview.2</NuGetBuildTasksPackVersion>
     <!-- Installer dependencies -->
     <MicrosoftNETCoreAppVersion>6.0.0-alpha.1.20612.4</MicrosoftNETCoreAppVersion>
     <MicrosoftNETCoreDotNetHostVersion>6.0.0-alpha.1.20627.5</MicrosoftNETCoreDotNetHostVersion>

src/libraries/Directory.Build.targets

@@ -127,6 +127,11 @@
     <PackageReference Include="Microsoft.DotNet.GenFacades" Version="$(MicrosoftDotNetGenFacadesVersion)" PrivateAssets="all" IsImplicitlyDefined="true" />
   </ItemGroup>
 
+  <!-- TODO: Remove when all required nuget pack features are part of the consumed SDK. -->
+  <ItemGroup Condition="'$(IsPackable)' == 'true' and '$(MSBuildProjectExtension)' != '.pkgproj'">
+    <PackageReference Include="NuGet.Build.Tasks.Pack" Version="$(NuGetBuildTasksPackVersion)" />
+  </ItemGroup>
+
   <Target Name="SetGenApiProperties"
           BeforeTargets="GenerateReferenceAssemblySource">
     <PropertyGroup>