IUnknown is also valid for IClassFactory (#89540)

Author: AaronRobinsonMSFT

src/coreclr/System.Private.CoreLib/src/Internal/Runtime/InteropServices/ComActivator.cs

@@ -123,7 +123,8 @@ private static object GetClassFactoryForType(ComActivationContext cxt)
                 throw new NotSupportedException(SR.NotSupported_COM);
             }
 
-            if (cxt.InterfaceId != typeof(IClassFactory).GUID
+            if (cxt.InterfaceId != Marshal.IID_IUnknown
+                && cxt.InterfaceId != typeof(IClassFactory).GUID
                 && cxt.InterfaceId != typeof(IClassFactory2).GUID)
             {
                 throw new NotSupportedException();