Alternatively: don't worry about keeping trunk "green" at all. Have a second branch called "stable" or something that auto-fast-forwards to latest trunk whenever trunk is green. Checkout stable, push new changes to trunk, avoid breaking CI, but if you break CI then don't worry about it, just push up a fix.
If you act like trunk is this "sacred" thing that must always be ready to deploy then what you end up with is a bunch of long-lived branches and PRs and all the merge conflicts and overhead that come with those.
If you act like trunk is this "sacred" thing that must always be ready to deploy then what you end up with is a bunch of long-lived branches and PRs and all the merge conflicts and overhead that come with those.