Testing strategy for groups with no SET

Why is this change being made?

As per feedback received in Product Development Flow v1.1 (Milestone 13.6) Changelog on Quad Planning - #10078 (closed), adding responsibilities for groups with no SETs.

The following discussion from !69131 (merged) should be addressed:

• @nagyv-gitlab started a discussion: (+4 comments)

  Not every group has a SET.

Author Checklist

• Provided a concise title for the MR
• Added a description to this MR explaining the reasons for the proposed change, per say-why-not-just-what
• Assign this change to the correct DRI
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