The type System.Collections.Generic.CollectionExtensions is defined in multiple seed assemblies.
The multiple assemblies are Microsoft.Extensions.DependencyModel.dll, System.Collections.dll.

This is a pre-existing issue that was discovered moving Microsoft.Extensions.DependencyModel into src\libraries, see #34296. We've suppressed the duplicate error for now.

To fix this, I recommend we rename the CollectionExtensions in Microsoft.Extensions.DependencyModel, which would be a breaking change.