For GitHub, they have rolled a merge queue system which is in beta: https://github.blog/changelog/2021-10-27-pull-request-merge-queue-limited-beta/ . When a pull request is approved, it is added in the queue and will be tested with all the other changes ahead in the queue which is exactly the system Zuul is using and @speck gave the link at https://zuul-ci.org/docs/zuul/latest/gating.html