Bump NuGet.Commands from 6.7.0 to 6.8.0 in /src/code (#1483)

Author: dependabot[bot]

src/code/Microsoft.PowerShell.PSResourceGet.csproj

@@ -14,11 +14,11 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="NuGet.Commands" Version="6.7.0" />
+    <PackageReference Include="NuGet.Commands" Version="6.8.0" />
     <PackageReference Include="NuGet.Common" Version="6.8.0" />
-    <PackageReference Include="NuGet.Configuration" Version="6.7.0" />
+    <PackageReference Include="NuGet.Configuration" Version="6.8.0" />
     <PackageReference Include="NuGet.Packaging" Version="6.8.0" />
-    <PackageReference Include="NuGet.ProjectModel" Version="6.7.0" />
+    <PackageReference Include="NuGet.ProjectModel" Version="6.8.0" />
     <PackageReference Include="NuGet.Protocol" Version="6.8.0" />
     <PackageReference Include="PowerShellStandard.Library" Version="7.0.0-preview.1" />
     <PackageReference Include="System.Net.Http" Version="4.3.4" />