I know more about AWS, but GCP from what I read is similar, best practice is that you have a web page that you authenticate to via SSO and get temporary access

I know more about AWS, but GCP from what I read is similar, best practice is that you have a web page that you authenticate to via SSO and get temporary access keys that you assign to environment variables. The SDK automatically knows how to read from the environment variables locally. When you run your code on the cloud platform, you attach privileges to the run time environment (VM, Lambda, docker runtime, etc) that are properly scoped for least privilege. The SDK also knows how to get your permissions from it automatically. You never need to worry about your code getting the proper access keys. I’ve done most of my CI/CD using AWS native services that you also attach the role to the runtime. For instance CodeBuild is really just a Linux or Windows Docker runtime that you can run anything in and you attach permissions to your CodeBuild project. Of course your AWS access is controlled ideally via your SSO or 2FA. I have done some work with Azure DevOps - which doesn’t have anything to do with Azure. You can also use it to deploy your AWS and you store your access keys in an Azure controlled vault and your pipeline gives AWS permissions to your scripts. I think the same thing works with GitHub Actions.