RCA of repo-updater change to determine why this failure occured

Created by: incident-io[bot]

https://github.com/sourcegraph/sourcegraph/pull/34845 was determined to be a likely root cause of #inc-99-cannot-add-repositories to cloud

(Please feel to reassign this to a more appropriate team)

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This action was created from Incident 99 (Cannot add repositories on Cloud) by Dax McDonald, using incident.io 🔥