That's the very thing we want to prevent by using unique download links.
If you still want to do this, you can download the binaries from SourceForge.
Though imo, it's still an abuse.

I mean I have an idea to store a copy if WinSCP portable inside the application folder or on the GitHub that can get outdated pretty quick.

So I'm working on the my app and I want to add WinSCP portable inside my app folder, so my app can call it and work with it any idea on how I can make my C# app download the portable executable because you have a secure link when you download the WinSCP software so I can't do direct download.