Add OpenSSF badge

[gab-arrobo]

Use the amf workflows (https://github.com/omec-project/amf/tree/main/.github/workflows) as a reference to enable/add the OpenSSF badge to this repository

[gab-arrobo]

@LinZiyuu, would you be interested in working on this? I can provide guidance. Please let me know. Thanks!

[LinZiyuu]

@gab-arrobo, thanks for the invitation! I am definitely interested in working on this.

Currently, I am focused on testing and fixing issues across multiple UPFs, so my bandwidth is a bit tight at the moment. Would it be okay if I reach out to you once I have some free time?

I'm really keen on becoming a contributor to the project, so I'd value your guidance.