Who says Azure devops is on the same infra as GitHub? I mean, sure they're both hosted in Azure data centers, but there's very little else shared between them AFAIK. I used to work for Microsoft and I heard about the grand plans to merge the two but I don't think it ever really happened.
Perhaps not 100% physically shared infra but there's references of architecture overlap such as "The GitHub-hosted runner application is a fork of the Azure Pipelines Agent."
