GenAPI expands interface heirarchy

[ericstj]

Describe the bug

When running GenAPI against a type that implements an interface with an inheritance chain every interface in the chain is listed.

To Reproduce

namespace n;
public interface I1 {}
public interface I2 : I1 {}
public interface I3 : I2 {}
public class C : I3 {}

Compile this and point GenAPI to it.

Expect : C to be emitted implementing only I3.

Actual:

namespace n
{
    public partial class C : I3, I2, I1
    {
        public C() { }
    }

    public partial interface I1
    {
    }

    public partial interface I2 : I1
    {
    }

    public partial interface I3 : I2, I1
    {
    }
}

Related: #32165

This is another case where the metadata is ambiguous. We could examine the list of interfaces and reduce it if we wanted brevity.

[ViktorHofer]

@ericstj do you think we should fix this during .NET 8 (i.e. for SBRP)?

[ericstj]

No, it's only cosmetic -- doesn't affect functionality.