[Windows build perf] ILlink should consume .NET assemblies from the Mac installation

[emaf]

Steps to Reproduce

Similar to #19511. The task ends up copying .NET assemblies and the Microsoft.iOS.pdb which already exist ont he .NET installation on the Mac

For a new MAUI app, the remote execution is checking and copying around 350 files that are declared that need to be copied to the Mac:

Build Logs

Binlogs.zip

[rolfbjarne]

We're planning on replacing our custom linker steps with other solutions for .NET 9 (#17693), and if we do so, it might be possible to run ILLink on Windows instead of remoting it.

However, we might not be able to finish the custom linker step removal in .NET 9, so we should also look into not copying BCL assemblies to the Mac as suggested.

[emaf]

Fixed in .NET 10 by Messaging updates.