macOS 14 Sonoma and Xcode 15 image support

Release notes

Using our SaaS runners on macOS, you can now build applications that require macOS in a secure, on-demand GitLab Runner build environment that's fully integrated with GitLab CI/CD on macOS 14 and Xcode 15.

Try it out today by using macos-14-xcode-15 as the image in your .gitlab-ci.yml file.

Description

As a macOS SaaS runner user, I would like to use the recently released macOS 14 with Xcode 15 as macos-14-xcode-15.