Remove PublishWindowsPdb & ConvertPortablePdbsToWindowsPdbs switches

[ViktorHofer]

Fixes #15724
Fixes dotnet/dotnet#1017

To double check:

• The right tests are in and the right validation has happened. Guidance: https://github.com/dotnet/arcade/blob/main/Documentation/Validation.md

[ViktorHofer]

@hoyosjs should the parts of https://github.com/dotnet/arcade/tree/main/src/Microsoft.DotNet.Internal.SymbolHelper that deal with pdb conversion be removed as well?

[akoeplinger]

I pushed that removal, let us know if it's still needed

[hoyosjs]

Last I checked, the gate still required it

[ViktorHofer]

the gate?

You mean the stargate? 😌

[hoyosjs]

Insertion gates. Just a few months ago insertions would fail without conversion.

[ViktorHofer]

VS shouldn't require Windows PDBs anymore. Roslyn doesn't produce them anymore (see the linked issue). Do you know to whom I can reach out to discuss this requirement? cc @marcpopMSFT