Bump NuGet.Protocol from 6.7.0 to 6.8.0 in /src/code (#1480)

Author: dependabot[bot]

src/code/Microsoft.PowerShell.PSResourceGet.csproj

@@ -19,7 +19,7 @@
     <PackageReference Include="NuGet.Configuration" Version="6.7.0" />
     <PackageReference Include="NuGet.Packaging" Version="6.7.0" />
     <PackageReference Include="NuGet.ProjectModel" Version="6.7.0" />
-    <PackageReference Include="NuGet.Protocol" Version="6.7.0" />
+    <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" />
     <PackageReference Include="System.Text.Json" Version="8.0.0" />