Create AI Use Case workstream to extend S2C2F guidance for Data Scientist persona

[adriandiglio]

This Issue establishes the formal creation of this workstream under the S2C2F Project within the Supply Chain Integrity WG with a workstream lead and contributors. Working doc: (link)

This workstream is in collaboration and jointly developed with the AI/ML Security WG. https://github.com/ossf/ai-ml-security/issues/22

The creation of this Issue closes the original community-contributed ask to extend S2C2F to cover AI Use Cases: https://github.com/ossf/s2c2f/issues/58