Update Dev on-call eligibility criteria to include (back) parts of Expansion Development

Why is this change being made?

As a result of https://gitlab.com/gitlab-com/business-technology/enterprise-apps/financeops/finance-systems/-/issues/1620+, ~100 engineers were removed from the Development on-call rotation and only Core Development remained participant.

After some quick analysis, this is a proposal to bring parts of Expansion Development back to being on-call (as they previously were), so there should not be any real changes.

TODO after merge

• After this is discussed and merged, we will still have to make the change in our on-call automations for it to take effect.
• Pipelines in the automation project and pagerslack will need to be re-triggered
• Extra 👀 check that the spreadsheet is now back to ~200 engineers and not ~100

Author and Reviewer Checklist

Please verify the check list and ensure to tick them off before the MR is merged.

• 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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• Assign reviewers for this MR to the correct Directly Responsible Individual/s (DRI)
  • If the DRI for the page/s being updated isn’t immediately clear, then assign it to one of the people listed in the Maintained by section on the page being edited
  • If your manager does not have merge rights, please ask someone to merge it AFTER it has been approved by your manager in #mr-buddies
  • The when to get approval handbook section explains the workflow in more detail
• For transparency, share this MR with the audience that will be impacted.
  • Team: For changes that affect your direct team, share in your group Slack channel
  • Department: If the update affects your department, share the MR in your department Slack channel
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  • Company: If the update affects all (or the majority of) GitLab team members, post an update in #whats-happening-at-gitlab linking to this MR
    • For high-priority company-wide announcements work with the internal communications team to post the update in #company-fyi and align on a plan to circulate in additional channels like the "While You Were Iterating" Newsletter

Commits

• Update Dev oncall elibility

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