How to publish iOS apps to the App Store with GitLab and fastlane

What this post added

This post details the integration of GitLab CI with fastlane for automated iOS app building and publishing to TestFlight. It covers the setup of CI/CD runners on macOS, the initialization of fastlane with `Appfile`, `Fastfile`, and `Gymfile` configurations, and the `.gitlab-ci.yml` file to orchestrate the build, signing, and deployment process. It also highlights the necessary environment variables for authentication with Apple's services.