Add Create: Source Code specialty to Jay McCure

Why is this change being made?

I am covering for Anastasia as SET for Source Code team, so I need to get pings such as: gitlab-org/gitlab#415200 (comment 1469202044)

https://gitlab.com/gitlab-org/quality/quality-engineering/team-tasks/-/issues/1680

Author Checklist

• Provided a concise title for this Merge Request (MR)
• Added a description to this MR explaining the reasons for the proposed change, per say why, not just what
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  • The when to get approval handbook section explains the workflow in more detail
• If the changes affect team members, or warrant an announcement in another way, please consider posting an update in #whats-happening-at-gitlab linking to this MR
  • If this is a change that directly impacts the majority of global team members, it should be a candidate for #company-fyi. Please work with internal communications and check the handbook for examples.

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