Investigate recurring CI issues and identify follow-up fixes

[laurenfrederick]

Summary

Investigate the CI instability affecting the team and identify the highest-impact root causes.

Goal

Produce a clear set of follow-up GitHub issues that capture specific, actionable fixes for the discovered CI problems.

Scope

• Review recent CI failures and flaky jobs in this repository
• Identify recurring failure patterns, affected workflows, and likely root causes
• Propose concrete remediation work items as individual follow-up issues

[j9liu]

@azrogers did some initial discovery for this:

• We have larger Windows/Linux runners already in the org, just need to change the name of the runner requested in our yaml.
• Custom Unreal images started on ci-custom-images but blocked by org permissions