Validate Microsoft.CodeAnalysis.Collections.Package on net6.0

[sharwell]

Follow-up to #57665

[jaredpar]

@sharwell you need to update the exclusions to include the new TF. Example is here

27e5492

These exclusions exist because the .csproj files for our source NuPkg use the following

    <DebugType>none</DebugType>

The rebuild leg requires a PDB (embedded or on disk) in order to execute the rebuild logic. Lacking a PDB the DLLs must be excluded from our rebuild work.

Ideally we'd just change this to have a PDB. It's unclear to me why it's explicitly turned off here.