Build SaaS MacOS runner's AMI with CI
The AMI we're using for our SaaS MacOS runner instances in AWS is build with packer from code (which is good), but for now it needs to be done manually from engineers computer (which is bad).
With https://gitlab.com/gitlab-org/ci-cd/shared-runners/images/aws/macos-nesting we will have that process automated and builds done with CI. The project will also allow to "publish" the built image from the staging environment to the production and sandbox ones. So that we don't need to re-build the same configuration over and over again.
Instead, we can use SaaS MacOS Staging runners environment as the place where images are being built as this is the place where we will first try to use them. After confirming that all works good we can use the "publish to SaaS MacOS Production" manual job to update AMI metadata and allow production environment account to use that image. After this the only thing left is to go to terraform and reconfigure our ASG