How we tripled max concurrent jobs to boost performance of GitHub Actions

This post details improvements to the GitHub Actions orchestration framework by changing the database schema to store state history in a separate table (`tbl_OrchestrationSessionEvent`) for incremental reads and writes, reducing CPU consumption for running orchestrations by 50% on average. It also details reducing postback load by stopping step status updates during workflow runs and only posting step data upon completion, and removing duplicated job completed events. These changes allowed GitHub Actions to run 3x more jobs concurrently on GHES machines.